Some Bettas can live happily in a community tank, others are pretty anti-social and want to live solitary.
You can try introducing the Betta last to the community, that way he hasn't established the tank as his territory, but be prepared that you may have to take him out again should he start harassing and attacking his tank mates.
Avoid placing fish with the Betta that have flowing fins and are very colourful! Also avoid placing him with aggressive fish, or fin nippers, or fast swimmers. Your Betta could get injured or stressed out, which lowers his immune-system, getting his fins nipped can start fin rot, which is very dangerous.