My guess is Miami, Va Tech & Auburn or Arkansas.
Auburn is in the lead for the two top local Alabama Corners McKinstry who's the #1 ranked CB in the 21 class & also sits in a good spot for Kamari Lassiter. Bama, LSU & Clemson are all still after McKinstry really hard, so that will be a recruitment that goes down to the wire & with Lassiter UGA, GTech, Clemson & Bama are all still interested but AU has a pretty firm lead there for right now. He's not a priority for AU, they want the local Bama boys first, they'd only push for him if they miss on Kinstry & Lassiter.
Va Tech already has DJ Harvey from Cali committed & a local VA kid in Shawn Asbury, the only reason why they're even still in it is because the CB's coach at IMG is a former VA Tech CB Antonio Banks (something I've already been telling the board for months) & he's selling Markevious on Va Tech heavy.
Arkansas has ATH AJ Green from Oklahoma (he's a RB but will play CB in college), Keaun Parker from Oklahoma & speedster Chase Lowery from Frisco TX all committed at CB, plus they're still trying to flip local Ark QB/CB Dreyden Norwood from TAMU.
Ole Miss is another school that was showing some interest in Markevious, they have ATH/CB Demarko Williams from GA & Trey Washington from Alabama committed at CB. Don't believe there's much interest here from Brown, at least there shouldn't be lol.
As far as Miami, don't wanna jinx it, but...

(If we find a way to fck this up we are mentally handicapped at CB crootin' lol, but yeah otherwise...)