In this study, we investigated the neutron-induced fissile isotopes of Protactinium-231 using the Coupled-Channeled Optical Model code (OPTMAN) up to 20 MeV. The research was driven by the growing demand for nuclear reactor fuels. Protactinium-231, a naturally occurring radionuclide with significant fuel potential, is found in nearly 100% abundance. When subjected to neutron bombardment, Protactinium-231 can yield fissile materials suitable for use as reactor fuel. We performed computations using two different approaches: The Potential Expanded by Derivatives (PED), which incorporates the Rigid-Rotor Model (RRM) treating nuclei as rigid vibrating spheres while considering nuclear volume conservation, and the Rotational Model Potentials (RMP), which accounts for the Soft-Rotator Model (SRM) treating nuclei as deformable, rotating spheres. Each set of calculated data was compared with data retrieved from the Evaluated Nuclear Data File (ENDF), and a high level of agreement was observed. In all cases, the threshold energies were found to be ≤ 4 MeV for both PED and RMP. Notably, the results obtained from the RMP approach exhibited closer agreement with the retrieved data than those from the PED approach.