Aromatic compounds are a class of compounds which obeys Huckel's (4n+2)π electron rule.
There are 3 conditions to be an aromatic compound:
1) The compound must be planar.
2)The compound must have conjugated system means alternate single and multiple bonds.
3) The compound must have (4n+2)π electrons in the ring.
The first member of the cycloalkane aromatic hydrocarbon is Benzene (C6H6) having planar shape, conjugation and 6π electrons.
So, cyclohexane does not belong to the aromatic class of the organic compounds.