v3.25.2
Cash and bank balances - Additional Information (Detail) - INR (₨)
₨ in Millions
12 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Balances with banks ₨ 27,552 ₨ 27,328
Bottom of range [member]    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Bank deposit, Maturity terms 8 days 8 days
Effective interest rate on Bank deposit 3.25% 3.00%
Top of range [member]    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Bank deposit, Maturity terms 3563 days 3653 days
Effective interest rate on Bank deposit 8.10% 8.27%