Since the question is here, I might as well answer it. You cannot safely keep male and female bettas together. Chances are either the male will kill one or more of the females or the females will gang up on him and kill him. They will not breed in a setup like this.
To breed bettas, you need to choose a pair, not more, then condition them carefully on livefoods while keeping them separate, then put them in a position where they can see each other but not get at each other until you are certain that they are ready (he is building bubble nest, she is showing breeding stripes- as opposed to stress stripes), then introduce them to each other while monitoring the situation carefully. Raising bettas is hard work, it will involve separate tanks for male and female+ a fry tank+ individual jars for male offspring once they sex out and before they can be sold. Lots of baby food, fed very frequently, lots of water changes.