Grandfather not giving father's share of property due to conflict

In my case, a land was purchased in 1977 in my father's name by my grand father. My father is eldest son among seven. My father was managing the family business and family property and documents since other were studying. With the passes of time due to some conflicts in family my father left everything, took loan from Bank and started his own business on a rented land . Now my grand father who is over 70 years is distributing his property among his sons except my father, blaming him that you may have stollen money when you were in control. My grand father possess more than 10 land ownership. My father thought that he is already having one property in his name so we can live with it. But when i checked at registrar office , my father's name was missing and it state that my grand father is owing this property. My father is sure that land was in his name since he use to manage all family document earlier. I want some guidance in this scenario, how can i get my share in family and the land