Wrong khata number on sale deed

Revenue records and actual possession and surveyor certificate establishes the ownership in case of a dispute.  If  B is in possession of the property, he should not part with possession and let 'A"s legal heirs proceed through court and claim the property..  B can defend the same

Thanks for your reply Sir, 

But I want to know on what basis B will defend the case as B has the wrong Khata No. in his sale deed 

Actual possession of the property, Mutation record with revenue authority.

Why "Suppose"? If a real time issue, please post complete facts.

But in the mutation paper also Khata No. is mentioned wrongly 

If the Khata number is wrong in the sale deed, then you may ask the seller to execute a register rectification deed to rectify the error.

Before that you ascertain the correct details including the actual khata number of the property you have purchased from the revenue department and issue a legal notice to the seller to rectify the error, failing to comply, you may file a suit for specific relief against the seller with a direction to execute a registered rectification deed.

If he still do not respond to the court summons or orders, you may get the deed executed through court. 

After rectification of this error nobody can claim any rights in your property for any reason.