If your grandfather is alive then it is not necessary or wajib for him to distribute his property. He has free will whether to distribute his property nor not. In case of his death, his property shall be divided among his three sons and one daughter. The land shall be divided into 7 shares. Out of the total each son shall get 2-2 shares and the daughter shall get 1 share provided his wife i.e. your grandmother is not alive. The detail of Shariah division is as follows:
Allah knows Best!
Darul Uloom Deoband