Buying a property of land whose Owner died 10 to 15 years before

Buyer Question to Lawyers: Shall I buy this property, whether this is legal if all are ready to sign in front of registrar, Will be any problem to me in future? Please suggest me after reading below... Buyer Question to Seller: Whose property is this? Seller Answer to Buyer: Property is in the name of my Father and Mother. Father died at the age of 77 (Year 2001) and mother died at the age of 77 (Year 2005) without any will. We are 8 children to our parents ( 6 daughters and 2 son). All the sisters were married and they are all with their families and out of which two of them were died. Myself and my younger brother are living in the above said property. Due to family situation we need to sell this property now. As I am the elder son taking steps to sell this property. But we don't have legal heir certificate and it is very tedious and time delay process to get the legal heir certificate at this current and urgent situation. Myself, my brother, all sisters who are live, husband including children of sister who are not live are ready to sign in front of registrar.