The whole BRSR filing obligation sits inside one sub-clause of one Regulation. Regulation 34(2)(f) of the SEBI (Listing Obligations and Disclosure Requirements) Regulations 2015 [L2-C1]. If you cannot cite this to a partner in a meeting, you cannot discuss BRSR credibly. Let us fix that.
What Regulation 34(2)(f) says
Regulation 34 lists everything a listed entity has to send to shareholders as part of its annual report. Sub-clause (2)(f) reads, in the operative part, that the annual report shall contain "a business responsibility and sustainability report, describing the initiatives taken by the listed entity from an environmental, social and governance perspective, in the format as specified by the Board from time to time." The Board here means SEBI. The format specified by the Board is the BRSR format at Annexure to SEBI Circular 10 May 2021 [L2-C2], updated by BRSR Core Circular 12 July 2023 [L2-C3].
Applicability is limited by a proviso. The BRSR filing is mandatory only for the top 1,000 listed entities by market capitalisation. Everyone below the top 1,000 threshold can file BRSR voluntarily; nothing stops them. But only the top 1,000 must file.
How the top-1,000 list is drawn
SEBI does not publish a fresh top-1,000 list every year. The stock exchanges do. BSE and NSE calculate market capitalisation of every listed entity as of 31 March of the financial year. The top 1,000 by that calculation constitute the BRSR-applicable cohort for the next filing. A company that was rank 987 on 31 March 2025 files BRSR for FY 2024-25 in its annual report for the year. A company that was rank 1,012 on 31 March 2025 does not have to file. That company can file voluntarily and many do, because ESG rating agencies and institutional investors expect BRSR data even from just-below-the-line entities.
The check you run in October
Every year, in October, the sustainability lead or the Company Secretary of a borderline listed entity runs this check. Two questions.
- What was your market capitalisation as of 31 March, based on the closing price on the primary exchange multiplied by shares outstanding?
- Where does that number rank against the closing market cap of all 3,900+ BSE and NSE listed entities as of the same date?
If your rank is 1 to 1,000, you file BRSR. If it is 1 to 150 (FY 2023-24), 1 to 250 (FY 2024-25), 1 to 500 (FY 2025-26), or 1 to 1,000 (FY 2026-27), you file BRSR Core and get reasonable assurance under SSAE 3410 [L2-C4].
Entering or exiting the cohort mid-year
Companies move up and down the market-cap ladder. A newly listed company that IPOs at rank 400 enters the BRSR-Core cohort immediately. A company whose share price falls sharply and drops from rank 800 to rank 1,200 exits the BRSR cohort at the next 31 March cut-off but must file the current-year BRSR for the year in which it was still inside the top 1,000. There is no proration. It is a snapshot on 31 March.
Voluntary continuation matters here. Once a company has established BRSR reporting infrastructure, exiting the cohort by falling below rank 1,000 does not usually stop the filing. ESG rating agencies keep asking. Institutional investors keep asking. So most companies continue on a voluntary basis. That is a positive Board decision, not a compliance requirement.
The overlap you cannot ignore
BRSR does not live alone in the annual report. It lives alongside Section 134(3) of the Companies Act 2013, which requires the Board Report to include specific disclosures on conservation of energy, technology absorption, foreign exchange earnings and outgo, and Section 135 CSR spend disclosures. It also lives alongside Regulation 34(3) LODR corporate governance report and the Directors' Responsibility Statement under Section 134(5). Some of the same numbers appear in multiple places. Getting them consistent across BRSR, Board Report, and CSR-2 filing is a Section 134 issue that a Company Secretary owns, not just a sustainability lead's problem.
A quick worked example
Take a hypothetical company. Assume market cap of Rs 8,500 crore as of 31 March 2026. Rank 620 among BSE and NSE listed entities. The company has to file BRSR for FY 2025-26. Because rank 620 is inside the top 500 cohort for FY 2025-26, the company has to obtain reasonable assurance on BRSR Core under SSAE 3410. If in FY 2024-25 the company had been rank 700 (outside top 500 but inside top 1,000), it would have filed BRSR that year but not obtained BRSR Core assurance. In FY 2025-26, its climb into the top 500 triggers assurance.
Notice what has to happen operationally. If assurance is required for FY 2025-26, the company must appoint an assurance provider under SSAE 3410 by roughly the second quarter of FY 2025-26, agree scope, run planning walkthroughs, provide evidence packs, and complete the assurance engagement in time for the annual report to be adopted at the AGM. That is a three-quarter workstream. It cannot start in Q4.
Next lesson: the nine NGRBC principles that structure Sections B and C. Twenty minutes of tour and you will be able to open any BRSR and know what each principle-wise page is about.