Am I obligated to pay my father 200 pounds monthly for the apartment I own, knowing that he is not in financial need and has already transferred ownership of real estate to my sisters and given them money?

If a father gifts an apartment to his son and hands it over to him, he has no right to demand rent, unless he retracts the gift, based on the saying of the Prophet, peace and blessings be upon him: "It is not permissible for anyone to give a gift and then retract it, except for a father concerning what he gives to his child." However, if he did not gift it but rather registered it in his name to be his after his death, then this is a will that is not effective unless approved by the remaining adult, sane heirs, based on his saying, peace and blessings be upon him: "There is no will for an heir unless the heirs approve." In this case, the apartment remains his property, and he has the right to demand rent. It is advised to treat the father with kindness and seek his pleasure, based on his saying, peace and blessings be upon him: "The father is the middle gate of Paradise."