Hydrokinetic technology is emerging as a promising renewable energy option for remote regions, offering a competitive alternative to traditional sources of power. The Savonius hydrokinetic turbine is a potential apparatus for extracting hydrokinetic energy from waterways and canals. The Savonius turbine has good self-starting qualities, a simple design, low torque ripple, etc. However, the main disadvantage of this turbine is its modest efficiency. In order to enhance the performance of the Savonius hydrokinetic turbine different slot shapes have been proposed. This study also highlights the effect of altered slot shapes. In this work, the SST \(k - \omega\) turbulence model has been employed. The inlet flow velocity considered for the present study was 1 m/s and the tip speed ratio ranges from 0.6 to 1.2. To visualize the flow, the flow distribution around the blade’s vicinity has also been discussed. Based on numerical results, the conventional slot (rectangular) shape has outperformed all other slot shapes. The maximum power coefficient of 0.2324 was achieved subsequent to the tip speed ratio of 0.9, which was about 25.4% higher than the turbine without a slot.