Can we give zakat to our brother or sister?
To understand the answer to this question, it is better to understand who is not eligible to receive zakat. Zakat cannot be given to Usool (father, mother, grandfather, grand-mother, etc) and Furoo’ (son, daughter, grandson, granddaughter, etc) and your wife/husband.
Hence, Zakat can be given to brother, sister, father’s brother/sister, mother’s brother/sister, brother/sister-in-law, stepmother, stepfather, etc. as long as they are eligible to receive the Zakat.
This last requirement of eligibility as a recipient means that you will have to inquire from them since their apparent living condition may not mean that they do not have saved gold or other assets more than Zakat Nisaab (benchmark) which makes them ineligible to receive Zakat. Many people do not liquidate their assets despite adverse conditions.