It's an original Gilaki(language of north of Iran) phrase which has a veriaty of definitions ranging from come on! or no kidding! when used in a friendly way, to go away, get the hell outta here or fuck off when used with anger. Baree individually means bro in Gilaki
1. For example when a strange boy comments shits on your girl's pic to flirt, you can reply to him "fakesh baree"
2. A: "that loner loser got a hot chick...khak ti sare mian(Gilaki; shame on you!)" B:"fakesh baree!"
it's an offensive term and means Fuck off in Gilaki.
(Gilaki is the language that people from north of Iran speak.)
Maria: come here and play with us John.
John: I'm so angry, Maria ! so FAKESH !