v3.26.1
Intangible Assets - Summary of Goodwill Impairment Test and Estimated Value in Use after Adjusting The Carrying Values of Assets and Was More Than Carrying Value Of Goodwill (Detail)
₨ in Millions, $ in Millions
Mar. 31, 2026
USD ($)
Mar. 31, 2026
INR (₨)
Mar. 31, 2025
USD ($)
Disclosure of information for cash-generating units [line items]      
Amount by which unit's recoverable amount exceeds its carrying amount | ₨   ₨ 65,090  
Ostro Energy Group [member] | Generation and Sale of Renewable Power [Member]      
Disclosure of information for cash-generating units [line items]      
Amount by which unit's recoverable amount exceeds its carrying amount $ 0   $ 5,615
ReNew Vayu Urja (KCT) [member] | Generation and Sale of Renewable Power [Member]      
Disclosure of information for cash-generating units [line items]      
Amount by which unit's recoverable amount exceeds its carrying amount 814   1,527
Prathamesh Solarfarms [member] | Generation and Sale of Renewable Power [Member]      
Disclosure of information for cash-generating units [line items]      
Amount by which unit's recoverable amount exceeds its carrying amount 813   970
Others [Member] | Generation and Sale of Renewable Power [Member]      
Disclosure of information for cash-generating units [line items]      
Amount by which unit's recoverable amount exceeds its carrying amount $ 1,529   $ 3,220