When brock returns will he just keep calling out taker until he gets a match?
I don't think he'll keep "calling" out Taker week after week, rather he'll get distracted by other opponents until then. Much like when Bo Dallas came out and distracted him.
I see Brock confronting Taker around Mania 32 and calling him out or interrupting him when Taker returns before Mania; at this point, another brawl may ensue. Taker will want to prove that he can b eat Brock at Mania, but we all know Taker will lose this time and they'll shake hands after the match.
Will he fight someone else like going back after rollins?
He may fight Rollins but right now Rollins is sidetracked with both Cena and Sting. That may happen for a couple more months; so, no, for the time being. I can see Brock not coming back until like Survivor Series and he may end up being a team captain and killing everyone. Maybe Kane will some vengeance and Brock will battle him at TLC or something. Who knows? But, there's options for sure.
How will they explain takers actions if he doesn't return until mania and will the rematch be at mania?
It'll be at Mania 32 for sure. They've already kind of explained it. He was desperate and wanted to slay Brock. Ref didn't see the tap out or low blow. It's cheap but he won and wanted to bring Brock down. Maybe Taker will come back and say he did what he did to motivate Brock to want another match with him at Mania 32, because Taker he feels he needs redemption. So he motivated the Beast to want to fight him yet again? Idk, that idea might work?