Buyers wants property document without paying last final amt

Buyers wants property document without paying last final amt . he cleared my mortgage property. he will give us the banker cheque at the time of registration once he receive the remaining loan amount from his bank. can we give the documents.

In Term and condition we mentioned that if the full amount is not paid within one month of agreeement. Then the agreement is canceled. Almost four months till today, We have financial problems waiting for the money what to do?