Thailand Institute of Nuclear Technology (TINT) is planning to develop Thailand Tokamak I from HT-6 M tokamak. In the first phase of operation, the device will be equipped with two fueling systems: gas puffing (GP) and supersonic molecular beam injection (SMBI). Since the SMBI system has never been used experimentally with this device, this work, therefore, numerically studies the penetration features of SMBI in the plasma of Thailand Tokamak I, based on the nominal parameters of HT-6 M tokamak. The interaction of the supersonic molecules with the plasma has been computed by BOUT++ code which solves six-field fluid model of SMBI model in the radial direction. The preliminary results demonstrate that the SMBI is an efficient method for fueling the plasma and the beam can be delivered to the center of the plasma core.