Foreign equity up to 51% is allowed for Multi-Brand Retail Trading (MBRT) subject to prior government approval. 
Since 2019, foreign investment in Single-Brand Retail Trade (SBRT) has been generally open to 100% foreign equity under the automatic route (without the need to obtain prior government approval), but certain restrictions apply in the some cases (see related other database entries). Previously, FDI above 49% in single-brand retailing was subject to prior government.

"CHAPTER 3: GENERAL CONDITIONS ON FDI [...]
3.4   ENTRY ROUTES FOR INVESTMENT 3.4.1 Investments can be made by non-residents in the equity shares/fully, compulsorily and mandatorily convertible debentures/fully, compulsorily and mandatorily convertible preference shares of an Indian company, through the Automatic Route or the Government Route. Under the Automatic Route, the non-resident investor or the Indian company does not require any approval from Government of India for the investment. Under the Government Route, prior approval of the Government of India is required. Proposals for foreign investment under Government Route, are considered by respective Administrative Ministry/Department. 
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3.5   CAPS ON INVESTMENTS
3.5.1 Investments can be made by person resident outside India in the capital of a resident entity only to the extent of the percentage of the total capital as specified in the FDI policy. The caps in various sector(s) are detailed in Chapter 5 of this Circular. 
3.6   ENTRY CONDITIONS ON INVESTMENT
3.6.1 Investments by non-residents can be permitted in the capital of a resident entity in certain sectors/activity with entry conditions. Such conditions may include norms for minimum capitalization, lock-in period, etc. The entry conditions in various sectors/activities are detailed in Chapter 5 of this Circular.
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5.2 PERMITTED SECTORS
a) In the following sectors/activities, FDI up to the limit indicated against each sector/activity is allowed, subject to applicable laws/regulations; security and other conditionalities. In sectors/activities not listed below, FDI is permitted up to100% on the automatic route, subject to applicable laws/regulations; security and other conditionalities. [...]
c) Foreign investment in sectors under Government approval route resulting in transfer of ownership and/or control of Indian entities from resident Indian citizens to nonresident entities will be subject to Government approval. Foreign investment in sectors under automatic route but with conditionalities, resulting in transfer of ownership and/or control of Indian entities from resident Indian citizens to non-resident entities, will be subject to compliance of such conditionalities. 
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5.2.15 TRADING [...]
5.2.15.2 E-COMMERCE ACTIVITIES
E-commerce activities  | % of Equity/FDI Cap: 100% | Entry Route: Automatic
5.2.15.2.1 Subject to provisions of FDI Policy, e-commerce entities would engage only in Business to Business (B2B) e-commerce [classified as wholesale activity] and not in Business to Consumer (B2C) e-commerce. 
5.2.15.2.2 DEFINITIONS:
i) E-commerce- E-commerce means buying and selling of goods and services including digital products over digital & electronic network. [...]
iii) Inventory based model of e-commerce- Inventory based model of e-commerce means an e-commerce activity where inventory of goods and services is owned by e-commerce entity and is sold to the consumers directly.
iv) Marketplace based model of e-commerce- Marketplace based model of e-commerce means providing of an information technology platform by an e-commerce entity on a digital & electronic network to act as a facilitator between buyer and seller. 
5.2.15.2.3  GUIDELINES FOR FOREIGN DIRECT INVESTMENT ON E-COMMERCE SECTOR 
i) 100% FDI under automatic route is permitted in marketplace model of e-commerce. 
ii)  FDI is not permitted in inventory-based model of e-commerce. 
5.2.15.2.4  OTHER CONDITIONS 
ii) Marketplace e-commerce entity will be permitted to enter into transactions with sellers registered on its platform on B2B basis.
iii) E-commerce marketplace may provide support services to sellers in respect of warehousing, logistics, order fulfillment, call centre, payment collection and other services. iv)  E-commerce entity providing a marketplace will not exercise ownership or control over the inventory i.e. goods purported to be sold. Such an ownership or control over the inventory will render the business into inventory-based model. Inventory of a vendor will be deemed to be controlled by e-commerce marketplace entity if more than 25% of purchases of such vendor are from the marketplace entity or its group companies. v) An entity having equity participation by e-commerce marketplace entity or its group companies, or having control on its inventory by e-commerce marketplace entity or its group companies, will not be permitted to sell its products on the platform run by such marketplace entity.
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5.2.15.3 SINGLE BRAND PRODUCT RETAIL TRADING 
Single Brand Product Retail Trading | % of Equity/FDI Cap: 100% | Entry Route: Automatic
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(2) FDI in Single Brand product retail trading would be subject to the following conditions: [...]
(e) In respect of proposals involving foreign investment beyond 51%, sourcing of 30% of the value of goods purchased, will be done from India, preferably from MSMEs, village and cottage industries, artisans and craftsmen, in all sectors. The quantum of domestic sourcing will be self-certified by the company, to be subsequently checked, by statutory auditors, from the duly certified accounts which the company will be required to maintain. This procurement requirement would have to be met, in the first instance, as an average of five years' total value of the goods procured, beginning 1st April of the year of the commencement of SBRT business (i.e. opening of the first store or start of online retail, whichever is earlier). Thereafter, SBRT entity shall be required to meet the 30% local sourcing norms on an annual basis. For the purpose of ascertaining the sourcing requirement, the relevant entity would be the company, incorporated in India, which is the recipient of foreign investment for the purpose of carrying out single-brand product retail trading. 
(f)    For the purpose of meeting local sourcing requirement laid down at para (e) above, all procurements made from India by the SBRT entity for that single brand shall be counted towards local sourcing, irrespective of whether the goods procured are sold in India or exported. SBRT entity is also permitted to set off sourcing of goods from India for global operations against the mandatory sourcing requirement of 30%. For this purpose, 'sourcing of goods from India for global operations' shall mean value of goods sourced from India for global operations for that single brand (in INR terms) in a particular financial year directly by the entity undertaking SBRT or its group companies (resident or non-resident), or indirectly by them through a third party under a legally tenable agreement.
(g) An SBRT entity operating through brick and mortar stores can also undertake retail trading through e-commerce. However, retail trading through e-commerce can also be undertaken prior to opening of brick and mortar stores, subject to the condition that the entity opens brick and mortar stores within 2 years from date of start of online retail. 
NOTE:
(i) Conditions mentioned at Para 5.2.15.3 (2) (b) & 5.2.15.3 (2) (d) will not be applicable for undertaking SBRT of Indian brands.
(ii) Indian brands should be owned and controlled by resident Indian citizens and/or companies which are owned and controlled by resident Indian citizens. 
(iii)Sourcing norms will not be applicable up to three years from commencement of the business i.e. opening of the first store or start of online retail, whichever is earlier for entities undertaking single brand retail trading of products having 'state-of-art' and 'cutting-edge' technology and where local sourcing is not possible. Thereafter, provisions of Para 5.2.15.3 (2) (e) will be applicable. A Committee under the Chairmanship of Secretary, DPIIT, with representatives from NITI Aayog, concerned Administrative Ministry and independent technical expert(s) on the subject will examine the claim of applicants on the issue of the products being in the nature of 'state-of-art' and 'cutting-edge' technology where local sourcing is not possible and give recommendations for such relaxation.  
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5.2.15.4 MULTI BRAND RETAIL TRADING
Multi Brand Retail Trading | % of Equity/FDI Cap: 51% | Entry Route: Government
(1) FDI in multi brand retail trading, in all products, will be permitted, subject to the following conditions: (i) Fresh agricultural produce, including fruits, vegetables, flowers, grains, pulses, fresh poultry, fishery and meat products, may be unbranded. (ii) Minimum amount to be brought in, as FDI, by the foreign investor, would be US $ 100 million. 
(iii) At least 50% of total FDI brought in the first tranche of US $ 100 million, shall be invested in 'back-end infrastructure' within three years, where 'back-end infrastructure' will include capital expenditure on all activities, excluding that on front-end units; for instance, back-end infrastructure will include investment made towards processing, manufacturing, distribution, design improvement, quality control, packaging, logistics, storage, ware-house, agriculture market produce infrastructure etc.  Expenditure on land cost and rentals, if any, will not be counted for purposes of backend infrastructure. Subsequent investment in backend infrastructure would be made by the MBRT retailer as needed, depending upon its business requirements.
(iv) At least 30% of the value of procurement of manufactured/processed products purchased shall be sourced from Indian micro, small and medium industries, which have a total investment in plant & machinery not exceeding US $ 2.00 million. This valuation refers to the value at the time of installation, without providing for depreciation. The 'small industry' status would be reckoned only at the time of first engagement with the retailer, and such industry shall continue to qualify as a 'small industry' for this purpose, even if it outgrows the said investment of US $ 2.00 million during the course of its relationship with the said retailer. Sourcing from agricultural co-operatives and farmers co-operatives would also be considered in this category. The procurement requirement would have to be met, in the first instance, as an average of five years' total value of the manufactured/processed products purchased, beginning 1st April of the year during which the first tranche of FDI is received. Thereafter, it would have to be met on an annual basis. [...]
(vi) Retail sales outlets may be set up only in cities with a population of more than 10 lakh as per 2011 Census or any other cities as per the decision of the respective State Governments, and may also cover an area of 10 kms around the municipal/urban agglomeration limits of such cities; retail locations will be restricted to conforming areas as per the Master/Zonal Plans of the concerned cities and provision will be made for requisite facilities such as transport connectivity and parking. [...]
(viii)  The above policy is an enabling policy only and the State Governments/Union Territories would be free to take their own decisions in regard to implementation of the policy.  Therefore, retail sales outlets may be set up in those States/Union Territories which have agreed, or agree in future, to allow FDI in MBRT under this policy. The list of States/Union Territories which have conveyed their agreement is at (2) below. Such agreement, in future, to permit establishment of retail outlets under this policy, would be conveyed to the Government of India through the Department for Promotion of Industry and Internal Trade and additions would be made to the list at (2) below accordingly. The establishment of the retail sales outlets will be in compliance of applicable State/Union Territory laws/ regulations, such as the Shops and Establishments Act etc.
(ix)  Retail trading, in any form, by means of e-commerce, would not be permissible, for companies with FDI, engaged in the activity of multi-brand retail trading. 
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5.2.15.5 DUTY FREE SHOPS 
Duty Free Shops | % of Equity/FDI Cap: 100% | Entry Route: Automatic [...]" (Government of India/Ministry of Commerce and Industry (2020), Consolidated FDI Policy (Effective from October 15, 2020))
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"Subject: Review of Foreign Direct Investment (FDI) policy on various sectors 
The Government of India has reviewed the extant FDI policy on various sectors and has made following amendments in the Consolidated FDI Policy Circular of 2017 (FDI Policy), effective from August 28, 2017, and as amended from time to time. 
[...]
4. Single Brand Retail Trading
Para 5.2.15.3 of FDI Policy is amended to read as under: 
Single Brand Product Retail Trading | % of Equity/FDI Cap: 100% | Entry Route: Automatic [...]" (Press Note No. 4 (2019 Series), DPIIT File No.: 5/3/2019-FDI Policy, dated 18.09.2019)
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Previously up to 2019
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"5.2.15.3 Single Brand Product Retail Trading 
Single Brand Product Retail Trading | % of Equity/FDI Cap: 100% | Entry Route: Automatic up to 49%/Government route beyond 49%  [...]" (Government of India/Ministry of Commerce and Industry (2017), Consolidated FDI Policy (Effective from August 28, 2017) )

Government of India/Ministry of Commerce and Industry (2020), Consolidated FDI Policy (Effective from October 15, 2020)
Press Note No. 4 (2019 Series), DPIIT File No.: 5/3/2019-FDI Policy, dated 18.09.2019
Government of India/Ministry of Commerce and Industry (2017), Consolidated FDI Policy (Effective from August 28, 2017)
[<a href="https://dpiit.gov.in/sites/default/files/FDI-PolicyCircular-2020-29October2020_0.pdf">Policy</a>],[<a href="https://dpiit.gov.in/sites/default/files/pn4_2019.pdf">PN</a>],[<a href="https://dpiit.gov.in/sites/default/files/CFPC_2017_FINAL_RELEASED_28.8.17_1.pdf">Policy</a>]