This paper presents the study of an unsteady rear stagnation point flow of an inclined magnetohydrodynamics Casson nanofluid in the attendance of mass transpiration and thermal radiation in energy equation. Graphene nanoparticles are immersed in the flow of a fluid for getting better rate of heat transfer. In this problem is given in nonlinear partial differential equation form and then it is mapped into nonlinear ordinary differential equation form, the resulting equation solved analytically with Biot number and then expressed the solution in closed form incomplete gamma function. The dual nature is also observed in the shrinking sheet case for certain values of parameters. Further, one solution for stretching sheet case. Impact of different parameters, alternates the performance of the entire flow in both stretching and shrinking case, the results can be discussed with the help of graphical representations. These problems arise in engineering field and industrial applications namely extrusion process, metal thinning, glass blowing etc.