Structure (i) : Planar, has resonance and has 4 π e− or 4nπ e− thus making it anti-aromatic.
Structure (ii) : Planar, has resonance and has 8 π e− or 4nπ e− thus making it anti-aromatic.
Structure (iii) : Non-planar, since sp3 hybridised carbon is there. So, non aromatic.
Structure (iv) : Planar, has resonance and has 4 π e− or 4nπ e− thus making it anti-aromatic.
Structure (v) : Planar , has resonance and has 6 π e− or (4n+2)π e−, i.e. it follows huckel rule, thus making it aromatic.
Structure (vi) : Planar , has resonance and has 6 π e− or (4n+2)π e−, i.e. it follows huckel rule, thus making it aromatic.
Total number of aromatic compounds are 2.