Formal:
* برادر (Barādar): This is the most common and general term for "brother," used in formal settings and when referring to a brother in a respectful way.
Informal:
* داداش (Dādash): This is a more informal and affectionate way to say "brother," often used between close friends or family members.
* برا (Barā): This is a very informal and casual way to say "brother," used mostly by younger people or between close friends.
Other options:
* برادرم (Barādaram): This means "my brother" and is used when you want to emphasize that the brother is yours.
* برادر بزرگ (Barādar bozorg): This means "elder brother" and is used to refer to an older brother.
* برادر کوچک (Barādar koochak): This means "younger brother" and is used to refer to a younger brother.
The best way to say "brother" in Farsi will depend on the specific situation and the relationship between the people involved.