The refractive index ( ) (Fig. ) describes the behavior of light propagating through the system. In particular, the value of the refractive index at zero photon energy gives the static refractive index (0). The value of (0) for p-BNC monolayer is 1.43 which is smaller than that value of penta-graphene(1.62) . This value slightly increases and reaches up to 1.46 at 6% of compressive strain. Meanwhile, the value of the refractive index at the higher range of photon energy shows that the value is the highest (1.60) at 1.76 eV. The value of the refractive index reaches 1.79 (at 2.71 eV) at 6% of compressive strain.