Commitments, liabilities and contingencies - Additional Information (Detail) - INR (₨) ₨ in Millions	12 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Statement [Line Items]
Disallowance of returned income with no impact on tax outflow	₨ 440
Unabsorbed losses or depreciation	0	₨ 0
Unused tax losses for which no deferred tax asset recognised	0
Commissioning Of Wind And Solar Energy Projects
Statement [Line Items]
Capital commitment	16,740	55,483
Financial gurantees given for renewable projects \| PPA
Statement [Line Items]
Financial guarantees renewable projects	₨ 14,875	₨ 13,218

The amount of future capital expenditures that the entity is committed to make.

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The amount of the estimated financial effect of possible assets that arise from past events and whose existence will be confirmed only by the occurrence or non-occurrence of one or more uncertain future events not wholly within control of the entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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The amount of unused tax losses for which no deferred tax asset is recognised in the statement of financial position. [Refer: Unused tax losses [member]]

+ References

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Financial guarantees renewable projects.

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Unabsorbed losses or depreciation.

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