v3.26.1
Property, plant and equipment (Details 2) - INR (₨)
₨ in Millions
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Disclosure of quantitative information about right-of-use assets [line items]      
Beginning balance ₨ 4,427 ₨ 3,007  
Depreciation for the year 1,702 1,249 ₨ 1,143
Ending balance 12,743 4,427 3,007
Gross carrying amount [member]      
Disclosure of quantitative information about right-of-use assets [line items]      
Beginning balance 7,748 6,381  
Additions 10,380 2,967  
Disposals (3,409) (1,743)  
Effect of changes in foreign exchange rates 407 143  
Ending balance 15,126 7,748 6,381
Accumulated depreciation [member]      
Disclosure of quantitative information about right-of-use assets [line items]      
Beginning balance 3,321 3,374  
Depreciation for the year 1,702 1,249  
Impairment 95    
Disposals (2,851) (1,353)  
Effect of changes in foreign exchange rates 116 51  
Ending balance 2,410 3,321 3,374
Land [Member]      
Disclosure of quantitative information about right-of-use assets [line items]      
Beginning balance 87 85  
Ending balance 103 87 85
Land [Member] | Gross carrying amount [member]      
Disclosure of quantitative information about right-of-use assets [line items]      
Beginning balance 87 85  
Additions 0 0  
Disposals 0 0  
Effect of changes in foreign exchange rates 16 2  
Ending balance 103 87 85
Land [Member] | Accumulated depreciation [member]      
Disclosure of quantitative information about right-of-use assets [line items]      
Beginning balance 0 0  
Depreciation for the year 0 0  
Impairment 0    
Disposals 0 0  
Effect of changes in foreign exchange rates 0 0  
Ending balance 0 0 0
Buildings [member]      
Disclosure of quantitative information about right-of-use assets [line items]      
Beginning balance 3,651 2,308  
Ending balance 11,414 3,651 2,308
Buildings [member] | Gross carrying amount [member]      
Disclosure of quantitative information about right-of-use assets [line items]      
Beginning balance 6,318 5,040  
Additions 9,382 2,353  
Disposals (2,941) (1,215)  
Effect of changes in foreign exchange rates 330 140  
Ending balance 13,089 6,318 5,040
Buildings [member] | Accumulated depreciation [member]      
Disclosure of quantitative information about right-of-use assets [line items]      
Beginning balance 2,667 2,732  
Depreciation for the year 1,278 944  
Impairment 95    
Disposals (2,445) (1,061)  
Effect of changes in foreign exchange rates 80 52  
Ending balance 1,702 2,667 2,732
Plant and equipment [member]      
Disclosure of quantitative information about right-of-use assets [line items]      
Beginning balance 0 0  
Ending balance 0 0 0
Plant and equipment [member] | Gross carrying amount [member]      
Disclosure of quantitative information about right-of-use assets [line items]      
Beginning balance 0 3  
Additions 0 0  
Disposals 0 (3)  
Effect of changes in foreign exchange rates 0 0  
Ending balance 0 0 3
Plant and equipment [member] | Accumulated depreciation [member]      
Disclosure of quantitative information about right-of-use assets [line items]      
Beginning balance 0 3  
Depreciation for the year 0 0  
Impairment 0    
Disposals 0 (3)  
Effect of changes in foreign exchange rates 0 0  
Ending balance 0 0 3
Furniture Fixtures And Office Equipment [Member]      
Disclosure of quantitative information about right-of-use assets [line items]      
Beginning balance 0 44  
Ending balance 0 0 44
Furniture Fixtures And Office Equipment [Member] | Gross carrying amount [member]      
Disclosure of quantitative information about right-of-use assets [line items]      
Beginning balance 0 82  
Additions 0 0  
Disposals 0 (82)  
Effect of changes in foreign exchange rates 0 0  
Ending balance 0 0 82
Furniture Fixtures And Office Equipment [Member] | Accumulated depreciation [member]      
Disclosure of quantitative information about right-of-use assets [line items]      
Beginning balance 0 38  
Depreciation for the year 0 0  
Impairment 0    
Disposals 0 (38)  
Effect of changes in foreign exchange rates 0 0  
Ending balance 0 0 38
Vehicles [Member]      
Disclosure of quantitative information about right-of-use assets [line items]      
Beginning balance 689 570  
Ending balance 1,226 689 570
Vehicles [Member] | Gross carrying amount [member]      
Disclosure of quantitative information about right-of-use assets [line items]      
Beginning balance 1,343 1,171  
Additions 998 614  
Disposals (468) (443)  
Effect of changes in foreign exchange rates 61 1  
Ending balance 1,934 1,343 1,171
Vehicles [Member] | Accumulated depreciation [member]      
Disclosure of quantitative information about right-of-use assets [line items]      
Beginning balance 654 601  
Depreciation for the year 424 305  
Impairment 0    
Disposals (406) (251)  
Effect of changes in foreign exchange rates 36 (1)  
Ending balance ₨ 708 ₨ 654 ₨ 601