<?xml version="1.0" encoding="UTF-8"?>
<!--CTW V1.0 (26-06-2026)-->
<xbrli:xbrl xmlns:in-capmkt="https://www.sebi.gov.in/xbrl/2023-06-30/in-capmkt" xmlns:in-capmkt-ent="https://www.sebi.gov.in/xbrl/Closure_Of_Trading_Window/2023-06-30/in-capmkt/in-capmkt-ent" xmlns:in-capmkt-roles="https://www.sebi.gov.in/xbrl/Closure_Of_Trading_Window/2023-06-30/in-capmkt-roles" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:nonnum="http://www.xbrl.org/dtr/type/non-numeric" xmlns:in-capmkt-type="https://www.sebi.gov.in/xbrl/2023-06-30/in-capmkt-types" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:net="http://www.xbrl.org/2009/role/net" xmlns:num="http://www.xbrl.org/dtr/type/numeric" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:iso4217="http://www.xbrl.org/2003/iso4217" xmlns:negated="http://www.xbrl.org/2009/role/negated" xmlns:xbrldi="http://xbrl.org/2006/xbrldi" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:xl="http://www.xbrl.org/2003/XLink"><link:schemaRef xlink:type="simple" xlink:href="in-capmkt-ent-2023-06-30.xsd"/><xbrli:context id="MainI"><xbrli:entity><xbrli:identifier scheme="https://www.sebi.gov.in/in-capmkt/ScripCode">500312</xbrli:identifier></xbrli:entity><xbrli:period><xbrli:instant>2026-09-28</xbrli:instant></xbrli:period></xbrli:context><in-capmkt:NameOfTheCompany contextRef="MainI">Oil &amp; Natural Gas Corporation Limited</in-capmkt:NameOfTheCompany><in-capmkt:NSESymbol contextRef="MainI">ONGC</in-capmkt:NSESymbol><in-capmkt:ISIN contextRef="MainI">INE213A01029</in-capmkt:ISIN><in-capmkt:TypeOfAnnouncementForClosureOfTradingWindow contextRef="MainI">New</in-capmkt:TypeOfAnnouncementForClosureOfTradingWindow><in-capmkt:TypeOfEventForClosureOfTradingWindow contextRef="MainI">Closure of Trading Window</in-capmkt:TypeOfEventForClosureOfTradingWindow><in-capmkt:DateOfStartOfTradingWindowClosure contextRef="MainI">2026-10-01</in-capmkt:DateOfStartOfTradingWindowClosure><in-capmkt:BriefDetailsForTradingWindowClosureEndDate contextRef="MainI">Trading Window of the Company will remain closed from 01.10.2026 till 48 hours after the declaration of Financial Results of the Company for the quarter and half year ended 30.09.2026.</in-capmkt:BriefDetailsForTradingWindowClosureEndDate><in-capmkt:PurposeOfTheClosureOfTradingWindow contextRef="MainI">For declaration of Financial Results of the Company for the quarter and half year ended 30.09.2026.</in-capmkt:PurposeOfTheClosureOfTradingWindow><in-capmkt:AnyOtherInformation contextRef="MainI">Pursuant to the provisions of SEBI (Prohibition of Insider Trading) Regulations, 2015 ("Regulations'') and the ONGC Policies, the Company had submitted Information to Stock Exchanges w.r.t. Annual Trading Window Closure Plan for Financial Year 2026-27 on 25.03.2026.</in-capmkt:AnyOtherInformation><in-capmkt:DateOfReport contextRef="MainI">2026-09-28</in-capmkt:DateOfReport></xbrli:xbrl>