Is it permissible for me to reclaim the land that was sold fraudulently by paying the amount my father received, and would it then become my sole property or belong to all heirs? And what about the amount I paid? Is it permissible for me to reclaim my uncle’s share in the same manner if his heirs appoint me as their agent?

If the sale was made by deceiving the buyer regarding the land area, then he has the right to annul the contract. If he does not annul it, the sale becomes binding. However, the deception by the agent does not justify annulling the sale with the buyer; rather, you should demand your right from the agent.

If the deception justifies annulment, and the land is returned, it becomes the property of all heirs, and it is not permissible for you to exclusively take any part of it. If you paid money on their behalf to recover the land, it is considered a loan, and you do not own their share through it. It is not permissible to stipulate that they sell you their share in exchange for the loan, nor is it permissible for them to sell you their share now, as they do not own it until the land is recovered.

It is advisable to refer to the Sharia court or knowledgeable scholars to determine the effect of the deception on the validity of the sale.