What to do i have invested on a disputed property

A property was under litigation. Both the plaintiff and defendant had agreed to sale this property to me I have executed the sale agreement followed by sale deed including all the concern person in the registered document. Now plaintiff has filed objection in revenue department to hold the transfer of khatta to me , reason stating that the case is pending in the court. The intention of plaintiff is to get more amount. As per Sale agreement i have made the payment the receipt is available, however out of two cheque , one cheque plaintiff has not presented to Bank. Now i required your suggestion.