In recent times, reversible logic has been fast tracked in an attempt to reduce the excess heat generation in conventional CMOS circuits so as to meet Landauer's limit of kTln2. This can be done in the most convenient way by utilising photons instead of electrons. There have been quite a few works carried out on various optical switches (OS) to implement optical reversible gates along with arithmetic and logical circuits. In this regard, the electro-optic Mach Zehnder interferometer (EO-MZI) is an efficient OS that initially employs electrode voltage to determine lights propagation path through it. This paper targets to explore a Titanium (Ti) diffused Lithium Niobate (LiNbO3)-based EO design of a reversible TR gate with an optimum MZI count. Furthermore, this TR gate is used to design an EO reversible 2:1 multiplexer, where the Feynman gate is embedded to act as a select line. The study also intends to design a 2N:1 RMUX with a full analysis of counts of ancilla inputs, garbage outputs, the Feynman gate, the TR gate, and the MZI. The design and simulation are carried out in the OptiBPM tool to verify the truth table, whereas the mathematical power modelling is validated through MATLAB. A system-level analysis of the TR gate is analyzed as a function of Ti diffusion length and wavelength in terms of extinction and coupling ratio.