Is the real estate office entitled to claim its commission in addition to the commission of the relative who claims to have been promised a month's rent in exchange for renting the house, or should the relative give the office's right from his share, and is the relative's money lawful for him if his claim is true?

It is permissible for your friend's relative, who acted as a broker, to take a fee for mediating between the seller and the buyer. It is also permissible for a broker to partner with another broker or to hire him to perform brokerage work, and the second broker is entitled to his fee or share from the first broker. The fee for the office that rented the house is obligatory upon your friend's relative, and the homeowner must pay the agreed-upon fee between him and his relative, and he owes nothing to the office.