Other Operating Income/(Loss), Net - Additional Information (Detail) - INR (₨) ₨ in Millions	12 Months Ended
Mar. 31, 2026	Mar. 31, 2025	Mar. 31, 2024
Disclosure of other operating income [line items]
Income tax relating to investment securities included in other comprehensive income	₨ (323)	₨ 83	₨ 259

The amount of income tax relating to amounts recognised in other comprehensive income in relation to investments in equity instruments that the entity has designated at fair value through other comprehensive income applying paragraph 5.7.5 of IFRS 9. [Refer: Other comprehensive income; Reserve of gains and losses from investments in equity instruments]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 12
-IssueDate 2025-01-01
-Paragraph 81
-Subparagraph ab
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=12&code=ifrs-tx-2025-en-r&anchor=para_81_ab&doctype=Standard
-URIDate 2025-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Note Expiry date 2027-01-01
-Name IAS
-Number 1
-IssueDate 2025-01-01
-Paragraph 90
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_90&doctype=Standard
-URIDate 2025-03-27

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration