Am I eligible for the share in my grandfathers property

We are two brothers and two sisters and I am the eldest son in my family.My sisters are married and we both brothers are married.As I am against dowry system so I convinced my family to marry girl of my choice as my father was forcing me to marry a girl who was perfect for me but his parents allured my parent to give a handsome dowry but I refused.I got married with my wife in 2004 and since then we both are living at my home along with my father and brother and his wife.But as I told you that my father forced me to marry that girl from whom he was getting dowry but my fathers that dream didn't became true so in frustration he started humiliating us as not giving food as we were not having much money at the time time we both started our life.He made fake complaints in local police station but after listening to us police asked them to not to do such bad act with us and asked to live peacefully but my father is of bad temperament and since then 14 years passed he continuously creating problem for us although he was a central government employee and was getting every benefits and now he is retired.I am working in private company where I am working hard to earn my bread and butter for both of us.Our home is in the name of my grandfather and trickly got a will created from my grandfather end in which he mentioned that I am not eligible for the property and neither my wife.Every where he spends money to get justice in favour of him.My mother was also a victim of domestic violence as my father was inclined towards my mothers younger sister and now he is as per his bad habit took my younger brothers wife in to this and is involved in bad activities and spending money on them because my brothe is not working and wherever he gets a job he left that company in not more than a month.So by doing this favour towards my father they are getting benefit. My mother was in favour of me but now she is no more.Now he wants us to leave the home but we don't want to leave that place as we are not financially strong to take this step.Also due to a law that if father wants he can give share in his property so he is misusing this law and now openly standing against us and says Ab kanoon bhi tumhari madad nahi karega mera makan hai main jisko chahu doo.Pls help we are in serious problem and till now survival is with the help