Tehsildar bribed to issue orders against the will

Hi, My Grandfather died a while back and he owned farm land(ancestral property). He had 3 sons and 5 grand sons. He left a will where he named the whole land on the names of his 5 grand children(I am one of them). But before the will could be executed, one of my uncles went to the Tehsil, bribed the Tehsildar and few other officials and got the land divided equally in 4 parts and got them named on the names of 3 sons and my grandmother. The case was filed to execute the will and the Tehsildar finally executed the will without conducting any hearing. My uncle appealed against it to Tehsildar and bribed the Tehsildar again and got a hearing done where the Tehsiladar has cancelled the order where the will was executed and has reinstated the order where the Land is named on the name of my Grand father's 3 sons and grandmother. My uncle is now selling the land on the his name and my Grandmother's(with her consent) name. But in the process, we Grandchildren are losing our ancestral property. What can be do legally to ensure that my grandmother's part of farm land cannot be sold. We tried to transfer the case by filing an application to District Magistrate but the Tehsildar conducted this hearing as soon as he got to know about the application and passed the order.