<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2016-12-05</periodOfReport>

    <dateOfOriginalSubmission>2016-12-05</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001040426</issuerCik>
        <issuerName>SYNTEL INC</issuerName>
        <issuerTradingSymbol>SYNT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001341807</rptOwnerCik>
            <rptOwnerName>Khanna Rakesh</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>404, RENAISSANCE</rptOwnerStreet1>
            <rptOwnerStreet2>LOKHANDWALA COMPLEX</rptOwnerStreet2>
            <rptOwnerCity>MUMBAI</rptOwnerCity>
            <rptOwnerState>K7</rptOwnerState>
            <rptOwnerZipCode>400053</rptOwnerZipCode>
            <rptOwnerStateDescription>INDIA</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Interim CEO and President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2016-12-05</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2927</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>19.9965</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>81527</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This line is amended to change the amount of securities acquired in Column 4 from 2,923 to 2,927 and to change the footnote to the price in Column 4 to revise the price range from a range of $19.99 to $20.00 per share to a range of $19.7173 to $20.00 per share.</footnote>
        <footnote id="F2">The price reported in Column 4 is a weighted average price.  These shares were purchased in multiple transactions at prices ranging from $19.7173 to $20.00 per share, inclusive.  The reporting person undertakes to provide to Syntel, Inc., any security holder of Syntel, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the ranges set forth in this footnote.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Byron S. Collier on behalf of Rakesh Khanna</signatureName>
        <signatureDate>2016-12-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
