It is permissible to give zakāh to brothers and sisters if you are not legally or religiously responsible for them. Religious responsibility means if they are disabled or have a sickness that prevents them from earning a living and their father is deceased. Legal responsibility means if a judge has ruled that you must support them due to a specific reason. If your brother does not fall under these two categories of responsibility, then it is permissible to give him from your zakāh, provided he is one of the eligible recipients mentioned in the verse from Sūrat at-Tawbah.
Fatwa issued by Dr. Khālid Naṣr