4-Tertiarybutylcyclohexanonethiosemicarbazone (4-TBCHTSC), crystallises in monoclinic crystal system with space group P21/c. The unit cell parameters were a=14.910(2) Å, b=8.3353(12) Å, c=10.5506(18)Å and α=90°, β=95.272(7)°, γ=90°, V=1305.6(4)Å3. Z = 4. From the obtained crystallographic data, the Cyclohexylidene ring structure adopts chair conformation and also the lengths of bonds in thiosemicarbazone moiety suggest extensive electron delocalization in it. Three intermolecular hydrogen bonds involving each sulphur atom results in a sheet like arrangement and the packing structure involves the arrangement of these sheets as layers without any interactions between them except van der Waals forces of attraction. Theoretical optimization of the crystal was done by computational methods using Gaussian softwares. FMO, MEP, NBO were detected and also molecular docking of the compound was done to detect its binding affinity towards anti apoptotic protein BCL2 and pro apoptotic protein BAX. Experimental in-vitro anti-proliferative activity study by MTT assay against SK MEL-28 cell lines suggest high cytotoxic activity, indicating possible use as a potential antitumor agent.