Legal Right of Ownership

My Grandfather were five brothers. His Eldest brother had purchased one property in Gurgaon during 1914. In the said property my grandfather and one more brother were living with their families along with their Eldest brother and his family. In 1940, some family disputes arises and eldest brother of my grand father asked my grand father to vacat the house. The matter was filed in the court. Court gives the decision during 1945 in my grand father's favour stating that he will not vacat the house and where he is living will continue to live. Decree of the court was paid of at that time. No appeal against the said decision was filed. My grand father was having 5 sons and 5 daughters. He died in 1964 and before he died, he made his will on plain paper that after his death the property where he is living will be in his wife name. That will is witnessed by the son of his Eldest brother. Son of Eldest brother of my grand father is still alive. He has sold the balance property in pieces to various persons. In 1975, through family settlement deed, the property of my grand father were divided among his sons and daughters. The portion which comes to my father was constructed by my father with his own earnings in 1975. The family settlement deed was signed by my grand mother in presence of Oath Commissioner who has counter signed the same but thereafter it was not submitted for registration. When my father approach to the son of his uncle grand father's with a request to sign the documents so that he could registered his portion with the concerned authorities in his name than he refused to sign the documents. My father is in the age of 80's and want to give his property which was constructed by him in 1975 between his two sons. Now, the question arises that - How the property will be registered in his name. - If the property is not in his name than how he will divide between his two sons. - If he want to register the property in his name now than can it be possible and if possible that what will be the procedure. - Can he make his will in regard to the property. -