I don't think Ohio State gets in unless everyone else has two losses. I think they get shut out at#5. If FSU loses tonight, you still have Baylor, ASU, Alabama, TCU, Oregon, and (likely) MSU ahead of Ohio State. ASU and Oregon play, so one of them is out, likely ASU.
That leaves Alabama (probably the best team in the country IMO), Oregon, TCU, Baylor, and (likely) MSU. TCU should be out if Baylor is in, because we should have no rematches in the final four unless everyone else has an insane number of losses. Same for Mississippi State. That being said, I think both Big 12 teams get in before Ohio State, though. And all this is assuming that FSU loses, which is looking less and less likely as the night goes on.