v3.26.1
Income taxes (Details Textual) - INR (₨)
₨ in Millions
12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Disclosure Of Movement in deferred tax assets and liabilities [Line Items]      
Deferred income taxes not recognized on undistributed earnings of subsidiaries ₨ 48,978 ₨ 43,442  
Exchange Differences on Foreign Currency translations Recognised In Income Statement On Deferred Tax ₨ 490 ₨ 10  
Effective tax rate 23.00% 25.00% 23.00%
Tax rate effect of tax losses 15.00%    
Top of range [member]      
Disclosure Of Movement in deferred tax assets and liabilities [Line Items]      
Effective tax rate 15.00%    
Profit Tax Impact [Member]      
Disclosure Of Movement in deferred tax assets and liabilities [Line Items]      
Uncertain tax positions ₨ 2,935 ₨ 2,875