possession of house

My Father payed Rs. 2,550,000 for a house in Faisal colony chaklala rawalpindi to my uncle. But he didn’t transfer registry and possession to my father. He waited 2 years for possession and registry but uncle was very smart to trap someone. and my father passed away in 2015 and it was the biggest tension for him before he died. leaving behind legal hiers 4 children, widow, and both parents. My grand Parents are totally in control of my uncle who is already a victim of clear fraud with my father. now instead of giving possession and registry of that house for which my father payed they are claiming more as per share of my grandparents from my father’s inheritance. They forcefully occupied another house which already on the name of my father in the name of my parents share which is rented and my uncle is collecting that rent. I want to know what is my legal status in this situation as i am losing 2 houses in the name of parents legal share in my father’s inheritance. these 2 houses amounting to about 60% of my father’s assets instead of 33% legal share of my grandparents. can i get justice If i go for Court case? Being a student i cannot follow and afford to much fee of court and legal adviser. if someone is willing to help me in legal proceeding. i will be very thankful.