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<xbrli:xbrl xmlns:in-capmkt="http://www.sebi.gov.in/xbrl/2025-11-30/in-capmkt" xmlns:in-capmkt-ent="http://www.sebi.gov.in/xbrl/Changes_In_Management/2025-11-30/in-capmkt/in-capmkt-ent" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:nonnum="http://www.xbrl.org/dtr/type/non-numeric" xmlns:in-capmkt-types="http://www.sebi.gov.in/xbrl/2025-11-30/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.w3.org/1999/xlink"><link:schemaRef xlink:type="simple" xlink:href="in-capmkt-ent-2025-11-30.xsd"/><xbrli:context id="MainD"><xbrli:entity><xbrli:identifier scheme="https://www.sebi.gov.in/in-capmkt/ScripCode">500313</xbrli:identifier></xbrli:entity><xbrli:period><xbrli:startDate>2026-05-21</xbrli:startDate><xbrli:endDate>2026-05-21</xbrli:endDate></xbrli:period></xbrli:context><xbrli:context id="MainI"><xbrli:entity><xbrli:identifier scheme="https://www.sebi.gov.in/in-capmkt/ScripCode">500313</xbrli:identifier></xbrli:entity><xbrli:period><xbrli:instant>2026-05-21</xbrli:instant></xbrli:period></xbrli:context><xbrli:context id="I_ChangeInManagement1"><xbrli:entity><xbrli:identifier scheme="https://www.sebi.gov.in/in-capmkt/ScripCode">500313</xbrli:identifier></xbrli:entity><xbrli:period><xbrli:instant>2026-05-21</xbrli:instant></xbrli:period><xbrli:scenario><xbrldi:typedMember dimension="in-capmkt:ChangeInManagementAxis"><in-capmkt:ChangeInManagementDomain>ChangeInManagementDomain1</in-capmkt:ChangeInManagementDomain></xbrldi:typedMember></xbrli:scenario></xbrli:context><xbrli:context 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id="D_ChangeInManagement2"><xbrli:entity><xbrli:identifier scheme="https://www.sebi.gov.in/in-capmkt/ScripCode">500313</xbrli:identifier></xbrli:entity><xbrli:period><xbrli:startDate>2026-05-21</xbrli:startDate><xbrli:endDate>2026-05-21</xbrli:endDate></xbrli:period><xbrli:scenario><xbrldi:typedMember dimension="in-capmkt:ChangeInManagementAxis"><in-capmkt:ChangeInManagementDomain>ChangeInManagementDomain2</in-capmkt:ChangeInManagementDomain></xbrldi:typedMember></xbrli:scenario></xbrli:context><xbrli:unit id="pure"><xbrli:measure>xbrli:pure</xbrli:measure></xbrli:unit><in-capmkt:NSESymbol contextRef="MainI">OILCOUNTUB</in-capmkt:NSESymbol><in-capmkt:NameOfTheCompany contextRef="MainI">OIL COUNTRY TUBULAR LIMITED</in-capmkt:NameOfTheCompany><in-capmkt:ScripCode contextRef="MainI">500313</in-capmkt:ScripCode><in-capmkt:MSEISymbol contextRef="MainI">NA</in-capmkt:MSEISymbol><in-capmkt:ISIN contextRef="MainI">INE591A01010</in-capmkt:ISIN><in-capmkt:WhetherDisclosureFiledForListedEntity contextRef="MainD">true</in-capmkt:WhetherDisclosureFiledForListedEntity><in-capmkt:RelationshipWithTheListedEntity contextRef="MainD">Listed Entity (self)</in-capmkt:RelationshipWithTheListedEntity><in-capmkt:WhetherEventOrInformationIsAnOutcomeOfBoardMeeting contextRef="MainD">true</in-capmkt:WhetherEventOrInformationIsAnOutcomeOfBoardMeeting><in-capmkt:DateOfBoardMeeting contextRef="MainD">2026-05-21</in-capmkt:DateOfBoardMeeting><in-capmkt:StartTimeOfBoardMeeting contextRef="MainD">12:00:00</in-capmkt:StartTimeOfBoardMeeting><in-capmkt:EndTimeOfBoardMeeting contextRef="MainD">16:05:00</in-capmkt:EndTimeOfBoardMeeting><in-capmkt:NumberOfPersonsOrEntitiesForWhomChangeIsBeingReported contextRef="MainI" unitRef="pure" decimals="0">2</in-capmkt:NumberOfPersonsOrEntitiesForWhomChangeIsBeingReported><in-capmkt:DateOfReport contextRef="MainI">2026-05-21</in-capmkt:DateOfReport><in-capmkt:TypeOfChange contextRef="D_ChangeInManagement1">Change in designation</in-capmkt:TypeOfChange><in-capmkt:CategoryForChange contextRef="D_ChangeInManagement1">Director</in-capmkt:CategoryForChange><in-capmkt:DesignationOfDesignatedPerson contextRef="D_ChangeInManagement1">Executive Director</in-capmkt:DesignationOfDesignatedPerson><in-capmkt:PreviousDesignationOfDesignatedPerson contextRef="D_ChangeInManagement1">Non Executive Non Independent Director</in-capmkt:PreviousDesignationOfDesignatedPerson><in-capmkt:PositionOfDirectorInBoardTwo contextRef="D_ChangeInManagement1">Not Applicable</in-capmkt:PositionOfDirectorInBoardTwo><in-capmkt:PositionOfDirectorInBoardThree contextRef="D_ChangeInManagement1">WTD</in-capmkt:PositionOfDirectorInBoardThree><in-capmkt:SalutationOfDesignatedPerson contextRef="D_ChangeInManagement1">Mr.</in-capmkt:SalutationOfDesignatedPerson><in-capmkt:NameOfDesignatedPerson contextRef="I_ChangeInManagement1">Paruchuri Dheeraj Chowdary</in-capmkt:NameOfDesignatedPerson><in-capmkt:EffectiveDateOfReasonOfChange contextRef="I_ChangeInManagement1">2026-06-01</in-capmkt:EffectiveDateOfReasonOfChange><in-capmkt:TypeOfChange contextRef="D_ChangeInManagement2">Appointment</in-capmkt:TypeOfChange><in-capmkt:CategoryForChange contextRef="D_ChangeInManagement2">Key Managerial Personnel</in-capmkt:CategoryForChange><in-capmkt:DesignationOfDesignatedPerson contextRef="D_ChangeInManagement2">Chief Financial Officer</in-capmkt:DesignationOfDesignatedPerson><in-capmkt:SalutationOfDesignatedPerson contextRef="D_ChangeInManagement2">Mr.</in-capmkt:SalutationOfDesignatedPerson><in-capmkt:NameOfDesignatedPerson contextRef="I_ChangeInManagement2">Ramamuni Reddy Jampanapalle</in-capmkt:NameOfDesignatedPerson><in-capmkt:EffectiveDateOfReasonOfChange contextRef="I_ChangeInManagement2">2026-05-21</in-capmkt:EffectiveDateOfReasonOfChange><in-capmkt:BriefProfile contextRef="D_ChangeInManagement2">He holds a Post Graduate Diploma in Marketing Management and an M.Com degree. He has over 35 years of extensive experience in the field of accountancy with Oil Country Tubular Limited and possesses significant expertise in finance and accounts management.</in-capmkt:BriefProfile></xbrli:xbrl>
