Is paying money to regain citizenship that was revoked from a Palestinian living in an Arab country considered forbidden (haram)?

There is no harm in paying money to a person to regain citizenship. If this person makes an effort for that, then it is considered a form of ijarah (hiring) or ju'alah (commission). However, if the money is a bribe, then it is haram (forbidden) for the recipient, not the giver, if the bribe is to obtain something to which one is not entitled. But if the bribe is to achieve a right or repel an injustice, then it is permissible according to the majority of scholars, and the sin is upon the one who takes the bribe. It is permissible to pay a bribe if one cannot obtain their right except by doing so.