Is the apartment given by the father to his son for marriage permissible if the father bought the house, which includes the apartment, with an interest-based loan?

The son must advise his father and command him to repent from borrowing with interest (riba). It is permissible for him to benefit from an apartment in the house that the father bought with the usurious loan, because the prohibition of the usurious loan is related to the borrower's liability, not to the specific asset itself.