Plot saled nd d buyer not getting registry done

Hlo der Sir we had saled a plot nd in aug 2013 d byna had done. D registry date was after 11 months from d byana date I.e in july 2014. The original byana contain only the signature of seller nd buyer nd not any of any1else. The buyer took d byana by saying dat I will give u photostat of byana tomorrow. It was decide dat half payment will b given within first 4 months. But given only 1/9 part dat too on requests. Wen d buyer gave us d byana so dat we may write the receiving on it We found dat d registry date was changed wid a black pen x.7.2014 was converted to x.9.2014 We were angry but that buyer is our known so we just ignored dat on his request. Now even today 26 June 2015 yet d registry is not done. Acc to rules if buyer do not stand by his words. The deal nd cancelled nd byana amount remain with seller. But dat buyer is teasing us nd saying to return money with interest. We have even sent a court notice that either get registry done within 15 days or deal will b cancelled nd no money will b returne::d. Even thode 15 daz have passed nd no rly from his side. We have marked our attendance on the 15th day in court nd he was still absent. I now wanna know dat r we free now to sale that property to some1else or shud keep it with us?