Which molecule is usually comprised of six carbons in a ring (with six sides)?

The hydrocarbon is usually named using the prefix that would indicate or entail how many carbon are present in it. For six carbons, the name would begin with hexa-. For cyclic molecule, the name would begin further with cyclo-. Thus, for the molecule that is described above, the name would be, cyclohexane. 

Another, more well-known, component is the cyclic molecule with alternating double bonds, this will be named, benzene.