ok this is my idea for the start (maybe)
You start as the exile, and you continiue were kotor II left off on. Your on the Ebon Hawk in unknown space. You might have some of your party members from kotor II, but most or some of them died out, since your in space for such a long time without supplies. Your still alive and ok since your jedi/sith. Soon, theres an incomimg ship or maybe he Ebon Hawk picks up a planet - or the remains of one. (since the true sith maybe desroyed it) Anyway. you land on the planet or board ship and meat find revan. When you find Revan, you begin to ask him all of your questions. But Revan dosnt have time because maybe the true sith are comming ng or something like that.
I dont know- this is just a quick answer from me- on how kotor III could be.