Finance costs and fair value change in derivative instruments - Summary of Detailed Information About Finance Costs and Fair Value Change in Derivative Instruments (Detail) ₨ in Millions, $ in Millions |
12 Months Ended | |||
|---|---|---|---|---|
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Mar. 31, 2025
INR (₨)
|
Mar. 31, 2025
USD ($)
|
Mar. 31, 2024
INR (₨)
|
Mar. 31, 2023
INR (₨)
|
|
| Disclosure Of Detailed Information About Finance Cost And Fair Value Change in Derivative Instruments [Abstract] | ||||
| Interest expense | ₨ 49,601 | $ 581 | ₨ 42,051 | ₨ 43,066 |
| Bank charges | 984 | 12 | 745 | 869 |
| Option premium amortisation | 601 | 7 | 1,900 | 2,510 |
| Loss on fair value changes on derivative instruments | 220 | 3 | 1,493 | 1,799 |
| Loss on account of modification of contractual cash flows | 0 | 19 | 1,277 | |
| Unwinding of discount on provisions | 773 | 9 | 977 | 953 |
| Unamortised ancillary borrowing cost written off | 173 | 2 | 321 | 492 |
| Total | ₨ 52,352 | $ 613 | ₨ 47,506 | ₨ 50,966 |