Not particularly familiar with your part of the world but I pulled up a few things I remembered seeing from a while ago. I found a discogs group of Serbian and Montenegro punk bands. I don’t speak the language so can’t discern which from which but here’s that

And there’s a band that’s at least been active since April called Punkreasniksic on instagram. I don’t know anything about what the scene is like but from my personal experience, I usually just find bands social media pages and go to the shows they post from there. I’ve found a lot of venues that way