Power of attorney for selling property

We have sold a property (house) in a village, which is on name of my father with his 2 brothers. My father & his 2 brothers are expired. There are appx. 31 members in family of my father & his 2 brothers. All are not possible to present in registar's office for sale document. So i want to make power of attorney on name of one or more family members. How can i do it ?.

Vinod