Female bettas can be kept in groups of 4-5 or more which spreads any agression, males under no circumstances should live together as basically they don't and you will end up with one fish that has killed any other male betta occupant. multiple males can live in divided tanks making sure each male has enough room and the dividers are not see through as the males will stress if they see other males in close proximity. I hope this helps.
I just re read the title....may be a stupid answer but....LOL nope, aggression between males and females is bad I would not keep them together