Recent research showed 4d, 5d transition metal oxide provides rich novel physical properties. A discovery of superconductivity in Sr₂RuO₄ is still controversial to verify the mechanism, and relativisitc Mott phase of Sr₂IrO₄ expanded wide research field of spin-orbit coupling-driven physics. As one step to explore the field, doping study also become vivid that it can alter the system's key parameters and artificially create a perturbed physical system. Rh doping in Sr₂IrO₄ revealled variation of spin-orbit coupling, and doping on electrons on Sr₂IrO₄ showed charge carrier dependent collapse of Mott phase. Now we tried to study doped compound Sr₂(Ru,Ir)O₄ to show the electronic propagation of bands and evolution of relativistic Mott phase with angle-resolved photoemission spectrscopy technique. With this presentation we would clarify the role of spin-orbit coupling on the crystal-field-dominating band structure of Sr₂RuO₄, and provide a step by step evolution of relativistic Mott transition from varying spin-orbit coupling parameter.