v3.26.1
Employee benefits (Details 4) - Parent Company Gratuity plan [member] - INR (₨)
₨ in Millions
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Disclosure of sensitivity analysis for actuarial assumptions [line items]      
Defined benefit obligation without effect of projected salary growth ₨ 3,212    
Add: Effect of salary growth 1,753    
Defined benefit obligation with projected salary growth 4,965 ₨ 3,863 ₨ 3,404
50 basis points increase [Member] | Discount rate [member]      
Disclosure of sensitivity analysis for actuarial assumptions [line items]      
Defined benefit obligation 4,815    
50 basis points increase [Member] | Salary growth [member]      
Disclosure of sensitivity analysis for actuarial assumptions [line items]      
Defined benefit obligation 5,121    
50 basis points decrease [Member] | Discount rate [member]      
Disclosure of sensitivity analysis for actuarial assumptions [line items]      
Defined benefit obligation 5,123    
50 basis points decrease [Member] | Salary growth [member]      
Disclosure of sensitivity analysis for actuarial assumptions [line items]      
Defined benefit obligation ₨ 4,816