grandfather property to my father

Dear Sir, I am from andhrapradesh. Our grandfather are two brothers. My grandfather is elder one and our property 15 acres on his name in revenue dept certificates. It is from their father property. Our younger grandfather doesn't not have anything on his name. But his sons are cultivating the land and they have also sold some part of their 7.5 acres share to third party. This is after death of my grandfather. During registration to third, party my father has also signed to sell the share of my younger grandfather. The third party persons got passbook for their 2 Acres. Now we want get passbook for our 7.5 acres on my father's name if possible on my name. In this case how to proceed. My father is only one son to my grandfather. But my younger grandfather has two daughters and two sons. Do we need to get sign from my aunts also if we go with partition process and notarised them in front of a lawyer to apply for passbook. Is it possible to get passbook by having partition agreement between my father and his cousins. Does it required to get sign from my. Aunts also in our father's part of agreement. They got married long back. Please suggest me.