Meet the concerned Sub Registrar and apprise him of the discrepancy in the record maintained in the office and get it corrected.

You can proceed with rectification process of the said EC entry

Make application to sub registrar office to rectify mistake in survey number 

enclose copy of sale deed wherein correct survey number is mentioned 

- Since , your sale deed is showing the correct Khata number , then the Registrar is bound to rectify the said error in the EC . 

- Move an application before the registrar with the copy of the sale deed , and request to rectify the errors made in the EC. 

- Further, as this is a clerical mistake , then no need to execute Rectification deed. 

If there occurred any error in the registered document either in the recital or details of the property,  then it can be rectified by executing a registered rectification deed. 

You may approach the vendor to execute a registered rectification deed to rectify the error. 

Move a representation in the SRO office seeking the requisite correction. Append a copy of the sale deed with your representation

Dear client,

To get the inaccuracies corrected in the Encumbrance Certificate, one needs to apply for the Rectification deed, with any accompanying proofs (if required), that substantiate the claim of the existence of an error in the certificate.

Thank you. 

You may please bring the discrepancy to the sub-registrar's notice in writing and request him/her to rectify. If there is no response, you may ascertain the status of your request through an RTI query. You may then complain to the Inspector General of Registration in your State and request him/her to direct the sub-registrar concerned to act on your request for rectification of the EC.