Breach of contract

The Sale deed registered in 1996 has attained finality and cannot be challenged.

However, show the document to a local prudent lawyer for better appreciation of facts and professional advise, if you feel.

If there is mentioned in any document of sale like in any receipt of payment or sale document etc, if there is no such thing and the sale document shows land measuring more than 4 acers then that is absolute. 

The sale is valid for sold extent only if it is excess then approch court and file declaratory suit for adverse possession on excess land.

If the property was sold in the year then what were you doing all these years?

It is very badly barred by limitation.

Do you say that the property sold was in exccess to the holding by the seller or the buyer has encroached excess property in excess to extent of the property he purchased?

This property was sold by someone in the year 1996, subsequently neither the same person nor his next generation heirs never questioned about the illegality  of this transaction, now how did you get this idea of the alleged discrepancy that you observe now.

How do you say that the amount received was for a lesser extent of land but the land was sold in excess to the amount received as sale consideration?

Were you present at the time of the transaction that took place?

Do you have any documentary evidence to prove your allegations?

I think you are wasting yor time on unnecessary and non maintainable things