My father had bought a property in 1981 and constructed house. He has his 3 siblings staying in the same house. The land was purchased on bond paper, it's not registered till date. My father passed away 3 years back, now his one sibling has demolished some part of house without our consent and started construction. The other sibling with help of gram panchayat and pdo has added his name in the village gram panchayat records. What would be the legal process to get the property registered on my name, my mother is still alive. Is it possible to take a legal action on them.