Property partition agreement

In 2007 some amount of land was allotted to the mechanical workers by the government in my home town. one of the worker has the no money to buy the land from the government and he approached my father. The agreement between my father and the worker was , my father has to pay the money until the land registered in the name of the worker, in return the worker has to give half of the land to my father. The agreement was done on 100 rupees NON JUDECIAL stamp paper with notary . my father paid the amount and the land registered in the name of the worker. But after the land registered in the name of the worker , the district collector had issued an order to stop the registrations in that particular area. so the until the further order issued no registrations will take place and the workers cannot sell or register their property. my father had died on August 21. Now the worker is refusing to obey the agreement and preparing himself to sell the whole land to someone else as soon as registration will begin. how can we proceed to get the land he promised to give us? i request the judicial experts.