Yes.If you free range you can put more birds in your coop. If you have small birds you can put more than 6 in. If the 6 birds meet your needs you are perfect! With smaller coops and lack of free ranging, some birds get bored, and some get mean. Some breeds of chickens were not designed to be *locked up*. However some breeds do very well with confinement. If you are adding birds, just do some leg work and choose what is right for the birds and right for you and you will do just great if you add birds..or don't.
If you do..we need pictures!!!