How big is your tank and how many females do you want? You need at least a 10 gallon tank with a minimum of 5 - 6 females to create a stable betta sorority tank. Please read up on sorority tank threads on this forum before trying it though because it can get VERY deadly without the proper care. Sororities are not recommended for beginners...
10 gallon planted - HMDT male betta, 4 peppered corys, assassin snails, Amano shrimp
10 gallon divided bare bottom - HMPK male, 2 VT males
29 gallon sorority planted [journal] - 6 females, 4 bronze corys, trumpet & nerite snails, 3 Amano shrimp