v3.26.1
Financial Instruments - Summary of Changes in Level 3 Assets and Liabilities (Detail)
₨ in Millions, $ in Millions
 12 Months Ended
Mar. 31, 2026
INR (₨)
Mar. 31, 2026
USD ($)
Mar. 31, 2025
INR (₨)
Disclosure of reconciliation of changes in fair value measurement assets liabilities [line items]      
Balance at the beginning of the year ₨ 1,286,520    
Balance at the end of the year 1,419,262 $ 15,127 ₨ 1,286,520
Level 3 [member] | Equity instruments [member]      
Disclosure of reconciliation of changes in fair value measurement assets liabilities [line items]      
Balance at the beginning of the year 17,391   20,126
Additions 2,038   1,925
Disposals [1],[2] (1,199)   (1,828)
Gain/(loss) recognized in consolidated statement of income 768   321
Gain/(loss) recognized in other comprehensive income (1,431)   (3,609)
Translation adjustment 1,876   456
Balance at the end of the year ₨ 19,443   ₨ 17,391
[1] During the year ended March 31, 2025, as a result of an acquisition by other investors, the Company sold its shares of equity instruments in six companies at a fair value of ₹ 1,281 and recognized a cumulative loss of ₹ 175 in other comprehensive income and cumulative gain of ₹ 152 in consolidated statement of income.
[2] During the year ended March 31, 2026, as a result of an acquisition by other investors, the Company sold its shares of equity instruments in three companies at a fair value of ₹ 585 and recognized a cumulative gain of ₹ 389 in other comprehensive income and cumulative loss of ₹ 138 in consolidated statement of income.