Among the most attractive light-absorbing materials, halide perovskites have been gaining popularity for their versatile range of use in solar cells, lasers, and photodetectors. Whereas, Titanium (Ti)-based all-inorganic perovskite solar cells (PSCs) have garnered attention for their optoelectronic capabilities in response to this situation. In this theoretical study, Cesium Titanium (IV) Halide based lead-free, eco-friendly, and stable Cs2TiCl6-based PSC has been proposed and a numerical simulation using SCAPS-1D has been carried out to enhance the cell performance by optimizing the device parameters. A different set of hole transport layers (HTLs) like MoO3, ZnTe, CNTS, CuAlO2, CdTe, nPB, C6TBTAPH2, N: TiO2, NiCo2O4, and PBTTT-C14 was simulated in combination with electron transport layers(ETLs) such as CdS, Nb2O5, ZnSe, and MZO. After several cell optimizations like thickness, acceptor, donor, and defect concentration of selected four structures, the best cell structure are suggested e.g., FTO/CdS/Cs2TiCl6/CdTe/Au that shows a PCE of 18.15% along with the short circuit current density (JSC) of 17.83 mA/cm2, open-circuit voltage (VOC) of 1.188 V, fill factor (FF) of 89.51%. Among all devices, the solar cell performance decreases when series resistance (RS) and temperature are increased as opposed to shunt resistance (RSh). The obtained results reveal that Cs2TiCl6-based PSC can contribute to the advancement of efficient non-toxic, all-organic perovskite solar cells in the future.