Provisions - Summary of Reconciliation of Changes In Provision for Decommissioning Costs (Detail) - Provision for decommissioning, restoration and rehabilitation costs [member] ₨ in Millions, $ in Millions |
12 Months Ended | |||
|---|---|---|---|---|
|
Mar. 31, 2025
INR (₨)
|
Mar. 31, 2025
USD ($)
|
Mar. 31, 2024
INR (₨)
|
Mar. 31, 2023
INR (₨)
|
|
| Disclosure of other provisions [line items] | ||||
| Beginning balance | ₨ 10,508 | ₨ 16,859 | ₨ 13,384 | |
| Arised during the year | 804 | 2,429 | 586 | |
| Disposal of subsidiaries | (61) | (149) | ||
| Unwinding of discount on provisions | 773 | 977 | 953 | |
| Adjustment during the year | (2,540) | (9,608) | 1,936 | |
| Ending balance | ₨ 9,484 | $ 111 | ₨ 10,508 | ₨ 16,859 |