v3.26.1
Segment information - Summary of Operating Segments (Detail)
₨ 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 operating segments [line items]        
Revenue ₨ 132,196 $ 1,409 ₨ 97,063 ₨ 81,319
Other income 11,072 118 6,383 7,309
Total income 150,635 1,605 109,070 96,531
Less: Employee benefit expenses 6,586 70 4,616 4,467
Profit before share of loss of jointly controlled entities and tax 13,997 149 10,056 8,297
Less: Raw materials and consumables 25,414 271 10,468 3,844
Less: Employee benefit and other expenses for non-reportable segments (20,055) (214) (12,783) (14,834)
Finance costs and fair value change in derivative instruments 61,754 658 52,352 47,506
(Loss)/ profit before tax 13,620 145 10,034 8,142
Less: Income tax expense 3,235 34 5,443 3,995
Profit/(loss) for the year 10,385 111 4,591 4,147
Operating segments [member]        
Disclosure of operating segments [line items]        
Other income 12,010 128 7,960 9,972
Total income 141,052 1,503 102,760 86,596
Raw materials and consumables used and changes in inventories of finished goods 21,125 225 7,991  
Less: Employee benefit expenses 5,043 54 3,398 2,536
Less: Other expenses 18,038 192 12,093 13,921
Total expenses 44,206 471 23,482 16,457
Profit before share of loss of jointly controlled entities and tax 96,846 1,032 79,278 70,139
Depreciation and amortisation expense (26,738) (285) (20,670) (17,583)
Change in fair value of warrants 184 2 595 551
Finance costs and fair value change in derivative instruments (61,754) (658) (52,352) (47,506)
(Loss)/ profit before tax 13,997 149 10,056 8,297
Less: Share of (loss) / profit of jointly controlled entities (377) (4) (22) (155)
Less: Income tax expense (3,235) (34) (5,443) (3,995)
Profit/(loss) for the year 10,385 111 4,591 4,147
Operating segments [member] | Other Segments [Member]        
Disclosure of operating segments [line items]        
Revenue 3,154 34 2,263 4,695
Less: Employee benefit expenses (941) (10) (128) (0)
Less: Raw materials and consumables (380) (4) (602) (3,844)
Less: Employee benefit and other expenses for non-reportable segments (1,124) (12) (82) (134)
Unallocated amounts [member]        
Disclosure of operating segments [line items]        
Other income 6,245 67 3,452 4,689
Less: Employee benefit expenses (602) (6) (1,090) (1,931)
Less: Employee benefit and other expenses for non-reportable segments (893) (10) (608) (779)
Generation and Sale of Renewable Power [Member] | Operating segments [member]        
Disclosure of operating segments [line items]        
Other income 10,896   7,901 9,972
Total income 99,092   89,507 86,596
Less: Employee benefit expenses 3,247   3,064 2,536
Less: Other expenses 14,295   11,368 13,921
Total expenses 17,542   14,432 16,457
Profit before share of loss of jointly controlled entities and tax 81,550   75,075 70,139
Manufacturing of Power Equipment's [Member] | Operating segments [member]        
Disclosure of operating segments [line items]        
Other income 1,773   59  
Total income 62,979   37,395 15,286
Raw materials and consumables used and changes in inventories of finished goods 40,583   30,015 14,289
Less: Employee benefit expenses 2,088   750 347
Less: Other expenses 5,012   2,427 650
Total expenses 47,683   33,192 15,286
Profit before share of loss of jointly controlled entities and tax 15,296   4,203  
Total Before Adjustments and Eliminations [Member] | Operating segments [member]        
Disclosure of operating segments [line items]        
Other income 12,669   7,960 9,972
Total income 162,071   126,902 101,882
Raw materials and consumables used and changes in inventories of finished goods 40,583   30,015 14,289
Less: Employee benefit expenses 5,335   3,814 2,883
Less: Other expenses 19,307   13,795 14,571
Total expenses 65,225   47,624 31,743
Profit before share of loss of jointly controlled entities and tax 96,846   79,278 70,139
Adjustments and Eliminations [Member] | Operating segments [member]        
Disclosure of operating segments [line items]        
Other income (659)      
Total income (21,019)   (24,142) (15,286)
Raw materials and consumables used and changes in inventories of finished goods (19,458)   (22,024) (14,289)
Less: Employee benefit expenses (292)   (416) (347)
Less: Other expenses (1,269)   (1,702) (650)
Total expenses (21,019)   (24,142) (15,286)
Revenue From External Customers [Member] | Operating segments [member]        
Disclosure of operating segments [line items]        
Revenue 129,042 1,375 94,800 76,624
Revenue From External Customers [Member] | Generation and Sale of Renewable Power [Member] | Operating segments [member]        
Disclosure of operating segments [line items]        
Revenue 88,196   81,606 76,624
Revenue From External Customers [Member] | Manufacturing of Power Equipment's [Member] | Operating segments [member]        
Disclosure of operating segments [line items]        
Revenue 40,846   13,194  
Revenue From External Customers [Member] | Total Before Adjustments and Eliminations [Member] | Operating segments [member]        
Disclosure of operating segments [line items]        
Revenue 129,042   94,800 76,624
Inter Segment Revenue [Member] | Manufacturing of Power Equipment's [Member] | Operating segments [member]        
Disclosure of operating segments [line items]        
Revenue 20,360   24,142 15,286
Inter Segment Revenue [Member] | Total Before Adjustments and Eliminations [Member] | Operating segments [member]        
Disclosure of operating segments [line items]        
Revenue 20,360   24,142 15,286
Inter Segment Revenue [Member] | Adjustments and Eliminations [Member] | Operating segments [member]        
Disclosure of operating segments [line items]        
Revenue (20,360)   (24,142) (15,286)
Revenue From Contracts With Customers [Member] | Operating segments [member]        
Disclosure of operating segments [line items]        
Revenue 129,042 $ 1,375 94,800 76,624
Revenue From Contracts With Customers [Member] | Generation and Sale of Renewable Power [Member] | Operating segments [member]        
Disclosure of operating segments [line items]        
Revenue 88,196   81,606 76,624
Revenue From Contracts With Customers [Member] | Manufacturing of Power Equipment's [Member] | Operating segments [member]        
Disclosure of operating segments [line items]        
Revenue 61,206   37,336 15,286
Revenue From Contracts With Customers [Member] | Total Before Adjustments and Eliminations [Member] | Operating segments [member]        
Disclosure of operating segments [line items]        
Revenue 149,402   118,942 91,910
Revenue From Contracts With Customers [Member] | Adjustments and Eliminations [Member] | Operating segments [member]        
Disclosure of operating segments [line items]        
Revenue ₨ (20,360)   ₨ (24,142) ₨ (15,286)