How can i get my share in grandmother's property in Muslim Law

I am an Indian male Muslim, My grandmother has written 50 years before a will that her house to my three brothers and two sister, during that time myself and my youngest sister were not born, half of the house has written to one of my brother and the rest of the house has written to all other brothers (two persons), two sisters. the property is not registered and only with help of lawyer (notary public), they have divided the property (house), they are saying that we (my self and my youngest) are not entitle to get the share the property, Is there any room to get my share accordance with proprty law?