v3.26.1
Provisions - Summary of Activity for Provision for Warranty and Other Provisions (Detail) - INR (₨)
₨ in Millions
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Disclosure of other provisions [line items]    
Balance at the beginning of the year ₨ 1,931 ₨ 1,971
Additional provision during the year 796 804
Utilized/written-back during the year (1,077) (854)
Translation adjustment 70 10
Balance at the end of the year 1,720 1,931
Provision for warranty [member]    
Disclosure of other provisions [line items]    
Balance at the beginning of the year 207 217
Additional provision during the year 214 207
Utilized/written-back during the year (207) (217)
Translation adjustment 0 0
Balance at the end of the year 214 207
Provision for onerous contracts [member]    
Disclosure of other provisions [line items]    
Balance at the beginning of the year 1,582 1,599
Additional provision during the year 582 597
Utilized/written-back during the year (826) (624)
Translation adjustment 70 10
Balance at the end of the year 1,408 1,582
Other provisions [member]    
Disclosure of other provisions [line items]    
Balance at the beginning of the year 142 155
Additional provision during the year 0 0
Utilized/written-back during the year (44) (13)
Translation adjustment 0 0
Balance at the end of the year ₨ 98 ₨ 142