My grandfather had purchased properties by his own income but registered all properties in my grandmother's name in 1960 later my grandfather in 1980 asked my grandmother to sign on a deed in which my grandmother relinquished all rights on the properties with two witness signed the deed but its not a registered deed.Later My grandfather on his deathbed in 1990 made a will giving all property to my uncle and not my father and later my grandmother in 1995 made a will giving all property to my father.My grandmother died in 2007, so is my grandmother's will valid ??