Some newer bands from SP: Futuro/B.U.S.H. (sort of post-punky), D.E.R. (grind, insane drummer), Nuclear Fröst crust, O Cúmplice [(crust)]9http://ocumplice.bandcamp.com/), but there are like really dozens of bands, more than one can remember, just browse their Facebook profiles and you're bound to see some concert announcements with other bands to check out (others from the top of my head: Rakta (post-punk/goth), O Inimigo (hc), Defy and Rot (though they're kinda big).
In Rio most punk concerts I've been to were at Audio Rebel or Estúdio Hanoi. Tomorrow I'll probably be going to a gig at Dona Vegana (vegan restaurant), it will be the second one there, there will probably be more. Some bands from Rio and surroundings: Sick Visions (I think these guys disbanded, haven't [heard](sickvisions.bandcamp.com) anything from them in ages), Parte Cinza (don't remember how they sound but found them cool live), Alchemists (same case, liked it but can't remember what they sound like, just [give it a go](thealchemists.bandcamp.com) and Deaf Kids (listen here).
From BH I'm far less knowledgeable. God Demise (crust), Expurgo (grind), Ereção de Elefante (grind), Martyrizer (old-school grind). By the way, I've seen most of these bands live at last year's Exhale the Sound, a very young but probably the best brazilian underground punk/metal festival. Too bad this year it's gonna be in November so you probably won't be able to attend.