If the town survey number is incorrect then you may have to get it rectified. 

For that you have to issue a legal notice to your vendor and demand him to rectify the error by executing a registered rectification deed. 

After the notice is returned undelivered you may execute a rectification deed,  if the registration department is not entertaining your deed then you can approach court with a suit for declaration to declare the correct town survey number and to direct the concerned registrar to register the rectification deed. 

If seller is not traceable you may file a suit before a court under Section 26 of Specific Relief Act 1963. The law provides for relief to parties in case the real intention of the party is not properly reflected in the documents executed because of a bona fide mistake of fact.

. 2) The court can direct the rectification of an instrument, if it is satisfied that the deed does not express the real intention of the parties. This relief is entirely discretionary.

Local lawyer can guide you as the total costs to be incurred in this regard 

A rectification deed is one for the purpose of correcting a technical flaw and does not involve any financial transaction. As such, it will not attract a stamp duty as a sale deed.

1. If the party 'A' can execute a Rectification Deed indicating the error in the sale deed and the correct New Town Survey Number for the property in your favour , then the problem would be solved. The Rectification Deed has to be registered in the jurisdictional Sub Registrar's Office.

2.  In case the party 'A' is not traceable to execute the registered Rectification Deed in your favour, then in that case, you can unilaterally execute a registered Declaration/ Declaratory Deed declaring the error which has crept in the sale deed and it's correction entering the correct New Town Survey Number and get it registered in the jurisdictional Sub Registrar's Office. 

Since this rectification deed do not alter the value of the property, there may not be any stamp duty but registration charges have to be paid.

You can contact a local document writer who will guide you properly 

Any typo error in name, date of death, boundaries, area, survey number etc.  can be corrected by registering a rectification deed. Presence of both seller and purchaser is required for registration of rectification deed, if any one is not present it is not possible to register rectification deed. As the  executant is not available, you need to take a direction from Court to Registrar for carrying out rectification. File a suit seeking direction to the  executant to join for registration of rectification deed also seek direction to Sub-Registrar for registration of rectification deed in case the  executant fails to appear. A direction will be given to executant to appear for registration of rectification deed in case he fails Sub-Registrar will register such deed.

- It can be corrected after executing a registered Rectification deed , but the appearance of both the parties are needed before the Registrar . 

- Since, they are not traceable then you can file a petition before the court for giving direction to the Registrar to correct the survey number. 

Yes rectification deed can serve the purpose