My answers are as follows:
1. In the family tree who are to be included ?
Ans: It must include great grand father down to great grand children. It is effective and valid genealogy.
2. The prospective buyer's lawyer says that all the members above 18 years of age should sign in the sale deed at the time of registration. Two of my nieces are abroad. It will be difficult for them to come and sign in the sale deed. My lawyer says they are not required to sign in the sale deed. Since we do not have any knowledge of law we are confused.
Ans: If co-parceners/ co-sharers then they have to give NOC or GPA or release deed or sign as consenting witnesses. Usually the buyers on faith as some of the family members permanently residing abroad may not return and claim the property, on such presumption without their signatures properties will be purchased.
3. In the event they are also required to be signed, can they execute a General Power of Attorney ? The buyers lawyer says 'No' whereas my lawyer says 'Yes'
Ans: Yes, they can. If they are not aggrieving with each other opinion of third expert may be obtained. Both of them seems to be acting to protect the interest of their respective clients.