بسم الله الرحمن الرحيم
(Fatwa: 1553/1284/B=10/1435)
It is not lawful to pay house rent with interest money which one receives from bank after depositing money in the bank. It is like using interest in one’s personal need, whereas it is not lawful to get benefit from interest money. It is wajib to give it in charity to poor and needy ones without the intention of reward. It is not lawful to use it in one’s personal need.
Note: You should not support him in this regard. It is not lawful. [N]
Allah knows Best!
Darul Ifta,
Darul Uloom Deoband