Roosters take a lot of experience. And eventually you could have multiple roosters, as in a large multi-generational flock. In smaller flocks, or flocks of just flock mates, not such a good deal. Roosters take more space.
Roosters raised with just flock mates rapidly outgrow the pullets, become sexually active long before the pullets are ready. Father/son rooster pairs tend to work better, but there is no for sure, failsafe plan for roosters.
Sometimes they begin to fight very early, sometimes they get a long until they have a knockdown drag out, sometimes once is enough, some will fight every day until one is dead. This is very upsetting to people and to the pullets.
If you have a only 6 birds, none of them should be roosters in my opinion.
Mrs K