Source: The Great Interpretation of Dreams (Ibn Sirin)
Seeing one's deceased brother in a dream indicates health and strength for the dreamer if the deceased is happy. If sad, it indicates weakness or worry.
Source: Perfuming Humanity in the Expression of Dreams (Al-Nabulsi)
Seeing one's deceased brother alive indicates the arrival of an absent person or gaining strength.
Source: Signs in the Science of Expressions (Ibn Shaheen)
Seeing one's deceased brother is interpreted according to his state, and may indicate a partner or friend.