v3.26.1
Share warrants - Schedule of Warrant Obligations (Detail) - Warrant
₨ in Millions, $ in Millions
12 Months Ended
Mar. 31, 2026
INR (₨)
Mar. 31, 2026
USD ($)
Mar. 31, 2025
INR (₨)
Mar. 31, 2024
INR (₨)
Disclosure of reserves within equity [line items]        
Beginning balance ₨ 190   ₨ 772 ₨ 1,309
Foreign currency translation 8   13 14
Converted to Public warrants  
Change in fair value (184)   (595) (551)
Balance 14 $ 0 190 772
Public Warrants        
Disclosure of reserves within equity [line items]        
Beginning balance 156   558 915
Foreign currency translation 8   10 9
Converted to Public warrants 14   78 32
Change in fair value (165)   (490) (398)
Balance 13 0 156 558
Private Warrants        
Disclosure of reserves within equity [line items]        
Beginning balance 34   214 394
Foreign currency translation   3 5
Converted to Public warrants (14)   (78) (32)
Change in fair value (19)   (105) (153)
Balance ₨ 1 $ 0 ₨ 34 ₨ 214