v3.26.1
Revenue - Additional information (Detail)
₨ in Millions, $ in Millions
 12 Months Ended
Mar. 31, 2026
INR (₨)
Mar. 31, 2026
USD ($)
Mar. 31, 2025
INR (₨)
Mar. 31, 2024
INR (₨)
Mar. 31, 2026
USD ($)
Disclosure of disaggregation of revenue from contracts with customers [line items]          
Impairment losses on receivables arising from contracts with customers ₨ 0   ₨ 0 ₨ 1,001  
Cost overruns recognized from contracts with customers 367   102 0  
Cost over-runs recognized from contracts with customers pending approval 3,110   3,477 3,578  
Revenue from contracts with customers 131,699   96,134 81,097  
Operating lease income included in revenue from contracts with customers 497   929 222  
Revenue recognized from cost over runs 297   99 110  
Revenue 132,196 $ 1,409 97,063 81,319  
Contract liabilities 1,639   1,240   $ 17
Wind Power [Member]          
Disclosure of disaggregation of revenue from contracts with customers [line items]          
Revenue 46,233   43,758 40,847  
Solar Power [Member]          
Disclosure of disaggregation of revenue from contracts with customers [line items]          
Revenue 39,967   35,611 33,521  
Hydro Power [Member]          
Disclosure of disaggregation of revenue from contracts with customers [line items]          
Revenue 1,996   2,237 2,256  
Over A Period of Time [Member]          
Disclosure of disaggregation of revenue from contracts with customers [line items]          
Revenue from contracts with customers 90,480   82,940 80,749  
At The Point of Time [Member]          
Disclosure of disaggregation of revenue from contracts with customers [line items]          
Revenue from contracts with customers 41,219   13,194 348  
Performance Obligations Satisfied [Member]          
Disclosure of disaggregation of revenue from contracts with customers [line items]          
Contract liabilities ₨ 1,240   ₨ 0 ₨ 0