The collapsing dynamics of relativistic fluid are explored in f(R) gravity in detailed systematic manner for the non-static spherically symmetric spacetime satisfying the equation of the conformal Killing vector. With quasi-homologous condition and diminishing complexity factor condition, exact solutions for dissipative as well as for non-dissipative system are found and the astrophysical applications of these exact solutions are discussed. Furthermore, it is demonstrated that f(R)=R, which is the extensive restriction of f(R) gravity, prior solutions of the collapsing fluid in general relativity, can be retrieved.