I’m in Korea and I ETS 1 year and a day after my DEROS date will I PCS and ETS back in the states?

Yes, you only need 6 months from your report date to your ETS to return to the states states for a short tour location, 12 months for a long tour location.
I would really suggest extending a year to take full advantage of a CONUS based SFLTAP program. There's so much you'll miss out on if you only have 6 months left when you arrive. For starters, up to 6 months of permissive TDY for job training or internship.

Yes, you will PCS back to the states. As long as you have 12 months you’ll be fine. Good luck to you....

Need to check with personnel, that's the safest thing to do.