Right of use assets - (Details 4) - INR (₨) ₨ in Millions |
12 Months Ended | |
|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
|
| Presentation of leases for lessee [abstract] | ||
| Additions to right-of-use assets | ₨ 1,456 | ₨ 2,692 |
| Additions to lease liability | 523 | 1,378 |
| IRU and deposit deferment under IFRS 9 | ₨ 933 | ₨ 1,314 |