Power of attorney

Since the title of property does not confer by power of attorney so your father can not be said owner of property.

I concur with the advise of expert Sh. Bhartesh Goyal. Payment of property tax do not confer title of the property besides execution of PoA by your grandfather in favour of your father.

The Supreme Court verdict, 2011 The 2011 order by the Supreme Court of India categorically states that the GPA is not an instrument of transfer when it comes to right, title and interest in an immovable property. The Court further held that power of attorney is only an agency created in favour of the recipient, also known as grantee, on behalf of the grantor. Moreover, even an irrevocable power of attorney does not have the effect of transferring title to the recipient. Therefore, GPA is not valid for the sale/purchase of a property. Transactions related to an immovable property can only be done by way of stamped and registered conveyance deed, as applicable under the respective State government Act. In the wake of the above decision, the Apex Court directed the municipal bodies not to register properties based on the GPA documents. However, genuine transactions done through GPA would remain valid.

Contact a local advocate and show the occupation and enjoyment of the property from last 25 years through Taxes, electricity bills, approvals, etc and get a declaration on adverse possession, He may explore such possibilities.

The PoA was given 25 years ago. Many a development would have taken since then. May be, there are different reasons why your father is paying land revenue and for your uncle's claim. Please post the complete facts esp. as to whether your grandfather is alive at present.