Generalization of brick wall method in Kerr-Newman Black Hole for entropy calculation

Using the brick wall method, we will calculate the entropy of Kerr-Newman black Hole and arrive at the already well established result. During the calculation, we will arrive at the generalized equation for FNSR and FSR mode of free energy, which can be used to evaluate the free energy of any black hole. And we will also show the detailed steps in our calculation to provide clarification about how we calculated it.