Property issue with father which he got from her wife gift will

We have one property where are I am leaving with my hindu family which is on my mother's name who is no more but before she died. She disowned me though public and private notice and make gift will to my father's name. During the court case in 2011 my father and me compromise and he allowed us to do construction on first floor and stay with family. But suddenly he got offer for someone and he want to sell that property so he forcing us to leave the property. Please suggest as we have invest huge amount in construction and suddenly this situation is very horrible.