To derive the I-V characteristics of a Gallium Nitride(GaN) based resonant tunneling diode. GaN is opted as it has a wide band gap of 3.4 eV, affords it special properties for applications in optoelectronic, high-power and high-frequency devices. To study the potential profile of the given RTD and also to find the Tunneling current density at various applied potential. Basically two methods are chosen, viz. Transfer matrix method and Finite difference method. The method which provides the best characteristic is chosen according to the situation.