sell of ancestral property

The buyer can buy undivided share and can partition the same from other cosharers at a later date,  hence the seller,  if having a right to sell the undivided share can proceed 

Yes, co-sharer can sell his undivided share to buyer and later on buyer can seek partition of property.

If the share in the property is not specified what will buyer buy, better to make a partition or let all the co sharers execute sale deed and all of them signing it with a simultaneous relinquishment deed from the seller in favour of other co sharers

The buyer has to approach court for partition.

Buyer can purchase undivided share out of the joint property and lateron file suit for possesson against all lthe coparceners.

Maloji Rao Ghodkar, Advocate