If you and your brother could manage to get together all siblings and prepare relinquish deed so you can first get property transfer on you name legally than can sell it easily.
That is only practical solution get relinquish deed. Than you tell me you are going to prove all other people are alive or not which are not staying there and out of station or out of country. After providing you any false decision tomorrow those people may come back and file case against you than again you are going to blame us.
If you still want to sell the ancestral property, at-least you have to take POA of all those people whom soever name is appearing on property family tree. You can't deny their share.
Here you can go for redevelopment procedure and take POA of all those siblings. Those who are staying Abroad kindly take their POA from Indian Embassy who is sitting in particular country.