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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2013-07-31</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001261166</issuerCik>
        <issuerName>NEUBERGER BERMAN REAL ESTATE SECURITIES INCOME FUND INC</issuerName>
        <issuerTradingSymbol>NRO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001097362</rptOwnerCik>
            <rptOwnerName>SUN LIFE FINANCIAL INC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>SUN LIFE ASSURANCE CO OF CANADA</rptOwnerStreet1>
            <rptOwnerStreet2>150 KING STREET WEST SUITE 1400</rptOwnerStreet2>
            <rptOwnerCity>TORONTO</rptOwnerCity>
            <rptOwnerState>A6</rptOwnerState>
            <rptOwnerZipCode>M5H 1J9</rptOwnerZipCode>
            <rptOwnerStateDescription>ONTARIO, CANADA</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>4.00% Mandatory Redeemable Preferred Shares due 09/14/2017</value>
            </securityTitle>
            <transactionDate>
                <value>2013-08-02</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>800</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>200</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote.</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>4.00% Mandatory Redeemable Preferred Shares due 09/14/2017</value>
            </securityTitle>
            <transactionDate>
                <value>2013-07-31</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>40</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1060000</value>
                    <footnoteId id="F4"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>840</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote.</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">On 08/02/2103, all of the stock of Sun Life Assurance Company of Canada (U.S.) which owns all of the stock of Sun Life Insurance and Annuity Company of New York, was transferred to Delaware Life Holdings LLC.  Thus, Sun Life Financial Inc. ceased to be the indirect owner of 800 shares directly owned by Sun Life Insurance and Annuity Company of New York.</footnote>
        <footnote id="F2">Sun Life Financial Inc. owns all of the common stock of Sun Life Assurance Company of Canada, direct owner of 160 shares and indirectly, through a series of holding companies, owns all of the common stock of Sun Life and Health Insurance Company (U.S.), direct owner of 40 shares.</footnote>
        <footnote id="F3">Sun Life Financial Inc. owns 100% of the common stock of Sun Life Assurance Company of Canada, direct owner of 160 shares and indirectly, through a series of holding companies, on such date owned all of the common stock of Sun Life Insurance and Annuity Company of New York, direct owner of 800 shares and 100% of the common stock of Sun  Life and Health Insurance Company (U.S.), direct owner of 140 shares acquired by Sun Life Insurance and Annuity Company of New York on 07/31/2013.</footnote>
        <footnote id="F4">Price paid by Sun Life and Health Insurance Company (U.S.), the direct owner of 40 shares, not by Sun Life Financial Inc.</footnote>
    </footnotes>

    <remarks>J = On 07/31/2013, Sun Life Insurance and Annuity Company of New York, then an indirectly wholly-owned subsidiary of Sun Life Financial Inc., sold 40 shares to Sun Life and Health Insurance Company (U.S.), another indirect wholly-owned subsidiary of Sun Life Financial Inc. Sun Life and Health Insurance Company (U.S.) does not have a CIK or CCC number at this time.</remarks>

    <ownerSignature>
        <signatureName>/s/ Stephen C. Peacher, signer for Sun Life Financial Inc. and Sun Life and Health Insurance Company (U.S.)</signatureName>
        <signatureDate>2013-11-21</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ John T. Donnelly, signer for Sun Life Financial Inc. and Sun Life and Health Insurance Company (U.S.)</signatureName>
        <signatureDate>2013-11-21</signatureDate>
    </ownerSignature>
</ownershipDocument>
