Is Panchayat Partition Valid Unregistered In Karnataka??

My grandfather had 2 younger brothers they had a property in their mother name(khatha) who was dead at that time. They did panchayat partition which is unregistered during that partition my grandfather's last brother who was a ill man gave half of his share to my father as my father was looking after him. The property which was 6 acre divided into 3 parts 2 acre for my grandfather 2 acre for second granddad and 2 for last one. Last one gave 1 acre for my dad in his partition deed. The khatha came to My father from his granny has khatha was in her name in revenue office. Now my Father's sister is asking for that property in court does our property remain within ourselves according to indian penal code. The partition happened in 1982 and my aunt filed case in 2015. Can we win our land