share of joint owners

First, need to check share of the each share holder as per se if any things not mentioned. What the prescribed law and quantum of share will be applicable in your instant case.

At the time of purchase of the property no share is mentioned among the joint owners, it is deemed to be the joint property of the 3 owners and has equal shares each.

Let us know which school of law you are? Hindu /Muslim law

So you three joint owners have an equal share of 1/3rd each.

If a property is held jointly by multiple individuals and the ownership shares of each joint holder are not defined in the agreement or in bank records, it is generally considered that each joint holder holds an equal share of the property, typically 1/3 for each joint holder.

However, joint holders can mutually agree or decide on the shares of each joint holder through a written agreement, which should be legally binding and should be registered bitlife with the relevant government authority. This agreement can also be used as evidence in case of any disputes.

If the joint owner are  as said by our lawyer faternity  rule 1/3rd will be govern whereas, if any previous testator had any wish by way of will or other instruments prior to his/her death that need to check. In your instant case, first you need to have yourself a mutual parition alloting your shares in family partition deed though its is not register not a problelms and same is present to bank or wherever the property situate and can obtain.