Once rights in father's property given up. Can they be restored?

Relinquishment must have been done by way of a relinquishment deed and this is a contract. 

Therefore, for revoking the relinquishment deed, you need to prove that either you did not have the capacity to contract or your consent was obtained by way of coercion, fraud, undue influence, misrepresentation or mistake.

If the same can be proven in the Court, then you can revoke your relinquishment deed.

Also, the relinquishment deed needs to be stamped and registered to be admissible in Court, if the legal formalities have not been complied then the same is invalid.

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