There are many variables...
Here's my best stab at it fwiw....
I wrote this big long breakdown of all possible scenarios and scrapped it....because it is lengthy and complex and instead will just say what is likeky.
What is likely is there are at least three teams tied based on conference records with 2 losses (out of UT, ou, ISU, and OSU) and likeliest tiebreakers are strength of wins/losses vs remaining big12 opponents outside of the tied group by ranking. So a win over the 4th ranked team trumps win over 5th place team and losses to a 7th placed team is worse than to a 6th etc. Two way ties when doing this are settled head to head. If this doesn't settle it then it goes to scoring differential within games between the tied teams and this will likely settle it.
Backing up, if a 3+ team tiebreaker isn't needed and only two teams are tied for the second spot then it is head to head only (and obviously one team was the clear #1 and is in).....for #2 spot.....>>>
2 loss osu trumps ISU
2 loss ou trumps UT and osu
2 loss isu trumps ou
2 loss UT trumps osu or isu
(This assumes ou gives osu their 2nd loss....otherwise ou is out, osu is in and UT vs ISU winner is in.....assuming no further losses for any team)
I have left kstate out as they lost their starting QB and I do not expect them to win out.
If they do, then UT is out and they beat ou and isu head to head and would be in if it is between two teams or if 3 teams invoIved see above. (I do not see them beating isu and UT, so again doubt this comes into play)
This is my best assessment and I'm sure I left somethings out.
The Big12 tiebreaker rules linked below.
Would love to hear critique or further analysis.
I, for the record, see a 4 way tie likely between ISU, OSU, ou, and UT..all with 2 losses..at the very least 3 of those.
What I do not know is what, if any, role the records including out of conference game plays. Seems it should matter on tiebreakers and would certainly affect isu and kstate but I do not see it referenced as far as initial determining factors.
The Big12 current rankings are shown to be:
ISU
OSU
KState
OU
UT
Yes. This was after scrapping the "long" version lol
Tiebreaker Procedures