Fdp negotiation settlement

What do you mean by the term 'FDP' used by you ?

Even other facts posted are not clear.

It's a FINAL DECREE PROCEEDING 

To avoid future litigation, the decision between a Property Buyback and a Court Settlement (Consent Decree) depends entirely on whether the involved parties are on friendly, cooperative terms.

In a court settlement/consent in  FDP decree, the agreement is recorded directly before the judge and embodied in the court’s Final Decree. Because it carries judicial authority, parties cannot file new suits later regarding the same claims (res judicata).

In the property  Buyback (Out-of-Court Settlement Deed), all parties are 100% cooperative and willing to execute a direct Sale Deed or Relinquishment Deed.Requires executing a registered Sale/Relinquishment Deed AND formally filing a memo to withdraw or close the pending FDP case. If the court case isn't formally closed, it leaves a technical loophole.

Thank You Sir this explains that relinquishment deed need to be executed to avoid future litigation.

The question is siblings filed a FDP should I request for NOC from their father. 

The query is short of material facts.