The depletion and the adverse effect on the environment caused by fossil fuels are critical reasons to divert the power generation medium into non-fossil fuels (hydro, wind, solar, and biomass). In recent years, the hydrokinetic system appeared as robust technology in the renewable power sector. The present study summarized the modifications done by various researchers on single and hybrid cross-flow HKT (hydrokinetic turbine) to enhance turbine performance characteristics. An effort has been made to present the experimental and numerical techniques for performance assessment of the cross-flow hydrokinetic system. There are various measuring instruments are available to measure the parameters such as water flow velocity, angular speed of the turbine, and torque output. These instruments, along with the experimental setup used by different investigators, have been reported in this study. There are various numerical methods are widely adopted to visualize the hydrodynamic behavior of hydrokinetic systems. Given this, several influential CFD parameters have been reviewed in the present study. This paper will assist in further development of the design and performance of the cross-flow hydrokinetic system.