Absence of proper deed of acquired land.

My grand mother was unmarried and she bought a land measuring 7 Katha in the year 1960. My father was adopted by her later. She consider my father as her foster child. Now my grand mother has one brother and he have 2 sons. One son is divorced having a child and other son is unmarried. Now my grand mother made a gift deed and gave 1 Katha from the 7 Katha land to my father, and made a will of 1 Katha for the child of her brother's son. And made a will for the rest of the land i.e 5 Katha land for her brother's wife and brother's divorced son. Now my father got probate of his 1 Katha land but rest part of the land which was mentioned in will was not probated by them, i.e 1 Katha land which was alloted to the child of her brother's son and 5 Katha land which was alloted to brother's wife and brother's divorced son jointly. Both of them didn't probated the will and left untreated. Now both of them died without having probated the will and they don't have their warisons as they are not married. Now my father got a Gift Deed of 1 Katha out of 7 katha property in the year 1990. And he is giving the land tax to the blro and holding tax of the whole property to municipality from the year 1990. But I don't have a deed of 7 katha property in my name. How will I be able to sell the property to someone without having the 7 katha deed only in my name? Buyers are always asking to me to provide 7 Katha land deed alloted on my name while buying but I am unable to provide the same. Facing problem in selling the property. Kindly help please give suggestions. There is no objection from anyone on my possession on the property since 1990.