Status Of Ancestral Property

My father sold a part of his land as he was unable to repay debt. The remaining part of the land is still with us. I am buying back the part of land sold by my father and consolidating the entire property. I would like to know if this consolidated property will be ancestral property or self-acquired property. Note: The part of the land which my father sold was never registered. It was a sale agreement on a notarized stamp paper.