Here, we have investigated structural deformation and mechanical properties of CrSSe with traditional Cr-metalbased chalcogenides. Similar to the TMDs Janus CrSSe is a stable compound with covalent bond between the TM and chalcogen atoms. The reliably negative values of cohesive strain increases the bond length between TM and Chalcogen atom whereas the thickness of monolayers decreases. Similarly, the bond angle between X-TM-X decreases due to the strain. The in-plane stiffness, shear and layer moduli, Poisson's ratio, ultimate bi/uni-axial stress of Janus CrSSe are in between the values of CrS 2 and CrSe 2 monolayers. This is due to the shorter bond length between Cr-S atoms resulting in the lowest cohesive energy in CrS 2 .