Well it really depends on your Betta, i got one in my community tank and he gets along with everyone, there are guppies, dwarf gouramis, danios, neons, a bristlenose and otos.
He was the only betta that i had that could go in there, he doesn't even flare at my other bettas. The other bettas will flare at the gouramis and guppies so he didn't got to get in and now he is in a barrack.
Try the guy, i floated my bettas when they were in their bags and saw their reaction, the most peaceful one got a probation period and he passed. Now he is swimming happily in the tank.