Answer:
(Fatwa: 238/238/M=1431)
Your brother should forsake the bad habits which made him debtor and he should adopt good habits. If you are not sadat (from the family of the Prophet, peace be upon him), you can give your zakah to your brother.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband
