Is it correct to sell gold to pay the Zakat on the money of the father who is sick with Alzheimer’s, and is it permissible to distribute the gold to needy siblings?

It is not permissible to dispose of the father's money except in a way that benefits him. Therefore, selling real estate is permissible if it is in his interest. Zakat on money must be paid if it reaches the nisab (minimum threshold) and a hawl (one lunar year) passes over it. It is preferable to invest the money for the father's benefit. It is not permissible to take from the money except for the amount of obligatory maintenance. If real estate is sold not for the father's benefit, then the disposal is void and the money must be returned.