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<!--REG30 V1.0 (16-10-2025)-->
<xbrli:xbrl xmlns:in-capmkt="http://www.sebi.gov.in/xbrl/2025-08-31/in-capmkt" xmlns:in-capmkt-ent="http://www.sebi.gov.in/xbrl/Regulation_30_Restructuring/2025-08-31/in-capmkt/in-capmkt-ent" xmlns:in-capmkt-roles="http://www.sebi.gov.in/xbrl/Regulation_30_Restructuring/2025-08-31/in-capmkt-roles" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:nonnum="http://www.xbrl.org/dtr/type/non-numeric" 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-2025-08-31.xsd"/><xbrli:context id="OneI"><xbrli:entity><xbrli:identifier scheme="http://www.sebi.gov.in/in-capmkt/ScripCode">500312</xbrli:identifier></xbrli:entity><xbrli:period><xbrli:instant>2026-10-08</xbrli:instant></xbrli:period></xbrli:context><xbrli:context id="OneD"><xbrli:entity><xbrli:identifier scheme="http://www.sebi.gov.in/in-capmkt/ScripCode">500312</xbrli:identifier></xbrli:entity><xbrli:period><xbrli:startDate>2026-10-08</xbrli:startDate><xbrli:endDate>2026-10-08</xbrli:endDate></xbrli:period></xbrli:context><xbrli:unit id="INR"><xbrli:measure>iso4217:INR</xbrli:measure></xbrli:unit><xbrli:unit id="pure"><xbrli:measure>xbrli:pure</xbrli:measure></xbrli:unit><in-capmkt:ScripCode contextRef="OneI">500312</in-capmkt:ScripCode><in-capmkt:NameOfTheCompany contextRef="OneI">Oil and Natural Gas Corporation Limited</in-capmkt:NameOfTheCompany><in-capmkt:NSESymbol contextRef="OneI">ONGC</in-capmkt:NSESymbol><in-capmkt:MSEISymbol contextRef="OneI">NOTLISTED</in-capmkt:MSEISymbol><in-capmkt:ISIN contextRef="OneI">INE213A01029</in-capmkt:ISIN><in-capmkt:TypeOfAnnouncementPertainingToRegulation30Restructuring contextRef="OneD">New</in-capmkt:TypeOfAnnouncementPertainingToRegulation30Restructuring><in-capmkt:TypeOfEventOfAnnouncementPertainingToRegulation30Restructuring contextRef="OneD">Acquisition of “to be incorporated companies”</in-capmkt:TypeOfEventOfAnnouncementPertainingToRegulation30Restructuring><in-capmkt:WhetherEventOrInformationDisclosedIsAnOutcomeOfBoardMeeting contextRef="OneD">false</in-capmkt:WhetherEventOrInformationDisclosedIsAnOutcomeOfBoardMeeting><in-capmkt:DateOfOccurrenceOfEvent contextRef="OneI">2026-10-07</in-capmkt:DateOfOccurrenceOfEvent><in-capmkt:TimeOfOccurrenceOfEvent contextRef="OneD">21:00:00</in-capmkt:TimeOfOccurrenceOfEvent><in-capmkt:DateOfReport contextRef="OneI">2026-10-08</in-capmkt:DateOfReport><in-capmkt:NameOfHoldingCompany contextRef="OneI">Oil &amp; Natural Gas Corporation Limited</in-capmkt:NameOfHoldingCompany><in-capmkt:RelationshipOfHoldingCompanyWithTheListedEntity contextRef="OneD">Listed Entity (self)</in-capmkt:RelationshipOfHoldingCompanyWithTheListedEntity><in-capmkt:NameOfTheIncorporatedEntity contextRef="OneI">ONGC Petrochemicals Marketing Limited</in-capmkt:NameOfTheIncorporatedEntity><in-capmkt:IndustryToWhichTheEntityBeingIncorporatedBelongs contextRef="OneI">Petrochemicals marketing and trading</in-capmkt:IndustryToWhichTheEntityBeingIncorporatedBelongs><in-capmkt:BriefBackgroundAboutTheEntityIncorporatedInTermsOfProductsOrLineOfBusiness contextRef="OneI">OPML has been incorporated as an integrated B2B marketing and trading platform for petrochemicals, chemicals and kindred products of the ONGC Group. Its activities include marketing, branding, business development, sourcing, trading, pricing, distribution, logistics, storage, customer management and sales and operations planning.</in-capmkt:BriefBackgroundAboutTheEntityIncorporatedInTermsOfProductsOrLineOfBusiness><in-capmkt:WhetherAnyGovernmentalOrRegulatoryApprovalsRequiredForTheIncorporation contextRef="OneD">Yes</in-capmkt:WhetherAnyGovernmentalOrRegulatoryApprovalsRequiredForTheIncorporation><in-capmkt:ProvideBriefDetailsOfAnyGovernmentalOrRegulatoryApprovalsForTheIncorporation contextRef="OneI">Approval of Department of Investment and Public Asset Management, Ministry of Finance was obtained.

Certificate of Incorporation was issued by the Registrar of Companies, Ministry of Corporate Affairs.</in-capmkt:ProvideBriefDetailsOfAnyGovernmentalOrRegulatoryApprovalsForTheIncorporation><in-capmkt:NatureOfConsiderationForIncorporation contextRef="OneD">Cash</in-capmkt:NatureOfConsiderationForIncorporation><in-capmkt:AmountOfCashConsiderationForIncorporation contextRef="OneD" unitRef="INR" decimals="-7">250000000</in-capmkt:AmountOfCashConsiderationForIncorporation><in-capmkt:DetailsOfConsiderationForIncorporation contextRef="OneI">Cash consideration through subscription to equity shares at face value.</in-capmkt:DetailsOfConsiderationForIncorporation><in-capmkt:CostOfSubscriptionOrThePriceAtWhichTheSharesAreSubscribed contextRef="OneD">Cost/Price</in-capmkt:CostOfSubscriptionOrThePriceAtWhichTheSharesAreSubscribed><in-capmkt:DetailsOfCostOfSubscriptionOrThePriceAtWhichTheSharesAreSubscribed contextRef="OneI">₹25 crore, representing subscription money by ONGC and its nominee shareholders to acquire 2,50,00,000 equity shares of ₹10 each.</in-capmkt:DetailsOfCostOfSubscriptionOrThePriceAtWhichTheSharesAreSubscribed><in-capmkt:PercentageOfShareholdingOrControl contextRef="OneI" unitRef="pure" decimals="INF">0.5</in-capmkt:PercentageOfShareholdingOrControl><in-capmkt:DateOfIncorporation contextRef="OneI">2026-10-07</in-capmkt:DateOfIncorporation><in-capmkt:CountryInWhichTheEntityIsIncorporated contextRef="OneI">India</in-capmkt:CountryInWhichTheEntityIsIncorporated><in-capmkt:AnyOtherBriefSignificantInformationForIncorporationEvent contextRef="OneI">OPML was incorporated in India on 07 October 2026 as a public limited company. It will undertake integrated marketing and trading of petrochemicals, chemicals and kindred products, along with related branding, business development, sourcing, pricing, distribution, logistics, storage, customer management and sales and operations planning. As a newly incorporated company, it has no turnover history for the preceding three financial years.</in-capmkt:AnyOtherBriefSignificantInformationForIncorporationEvent></xbrli:xbrl>
