Actually, I believe odd regions host in odd years. Also, District 5 & 6 make up Region 3, while Districts 7 & 8 make up Region 4.
This year, HHS or CCHS will (barring a tear in the space/time continuum) host the regional final (3rd round) and would travel for the semi-state (4th round).
Boyle/LexCath - D5
Rockcastle/Knox Central - D6
Highlands/CovCath - D7
Ashland/Johnson Central - D8