The conventional slow evaporation technique is used in the growth of semi-organic single crystals of Hexa aqua nickel bis (P-toluene sulfonate) (HNPS) and the monoclinic system with centrosymmetric space group (P21/n) is corroborated by single-crystal X-ray diffraction analysis. FTIR vibrational analysis inferred the presence of water molecules CH3 and SO3 groups in grown HNPS crystals. Linear optical parameters explored by UV–Visible spectral analyses ensures the high optical activity of HNPS. The green light emission of HNPS was attributed to Photoluminescence analysis. Thermal analysis encapsulates the thermal stability of HNPS crystals up to 590 °C. The dielectric nature of the material was analyzed for various frequencies at room temperature and an increase in DC conductivity of HNPS suggests the semiconducting behavior of the material while heating. The work hardening coefficient is quantified as 3.7 using mechanical analysis. The thermal and mechanical stability suggests the specific application of HPNS in device fabrications. The synthesized HNPS was tested against two gram-positive bacterial strains (Bacillus subtilis, Staphylococcus aureus) and two gram-negative bacterial strains (Escherichia coli, Pseudomonas aeruginosa) and showed higher significant antibacterial activity against the pathogen.