AbstractOptomechanics is a growing field of research, studies the interaction between optical field and mechanical oscillator. In this study, we theoretically analyze a hybrid system which consists of Fabry Perot cavity containing two‐level N‐ Number of atoms. The cavity having two mirrors one is fixed, and other is oscillating. The oscillating mirror has a position dependent mass, considered as effective mass. The mechanical resonator generates a nonlinear effect because it is position dependent. Dynamics of the system's operators, steady‐state solutions, and optical response of the hybrid optomechanical system are analytically calculated. Optical response in the regime of position dependent effective mass (PDEM) are the main result in this article. We deduced that position dependent parameter of the resonator not only effect the dynamics but also the optical response of the optomechanical system.