  A central problem in General Relativity is obtaining a solution to describe
the source's interior counterpart for Kerr black hole. Besides, determining a
method to match the interior and exterior solutions through a surface free of
predefined coordinates remains an open problem. In this work, we present the
ansatz formulated by Newman-Janis to generate solutions to the Einstein field
equation inspired by the mentioned problems. We present a collection of
independent classes of exact interior solutions of the Einstein equation
describing rotating fluids with anisotropic pressures. Furthermore, we will
elaborate on some obtained solutions by alluding to rotating wormholes.
