Win out, go to the Rose Bowl (at least).

Teams that can still make the PAC 12 title game are as follows:

North:
Oregon (win out or only lose 1)
Oregon State (needs to win out and needs Oregon to lose one more game)

South:
Utah (win out, lose one and have UCLA and USC lose too)
UCLA (win out)
USC (win out, Utah loses one)

There may be a scenario where Stanford (3-3) or ASU (2-3) make the title game due to weird multi-team ties and tiebreakers, I'm not sure. But barring some very weird situation where Oregon loses out or Utah loses 2 of the last 3, those 5 teams are the only ones with realistic chances to make the PAC 12 title game.

Here's the FPI schedules for all 5 of them:
Oregon: Arizona (96.5%), @ASU (84.1%), OSU (95.5%)
Utah: UCLA (89.2%), @Arizona (88.6%), CU (94.8%)
USC: @ASU (53.3%), Cal (66.3%), UCLA (74.2%)
UCLA: @Utah (10.8%), @USC (25.8%), Cal (64.8%)
OSU: UW (18.7%), ASU (44.1%), @WSU (16.2%), @Oregon (4.5%)