  The strong gravitational field near massive blackhole is an interesting
regime to test General Relativity(GR) and modified gravity theories. The
knowledge of spacetime metric around a blackhole is a primary step for such
tests. Solving field equations for rotating blackhole is extremely challenging
task for the most modified gravity theories. Though the derivation of Kerr
metric of GR is also demanding job, the magical Newmann-Janis algorithm does it
without actually solving Einstein equation for rotating blackhole. Due to this
notable success of Newmann-Janis algorithm in the case of Kerr metric, it has
been being used to obtain rotating blackhole solution in modified gravity
theories. In this work, we derive the spacetime metric for the external region
of a rotating blackhole in a nonlocal gravity theory using Newmann-Janis
algorithm. We also derive metric for a slowly rotating blackhole by
perturbatively solving field equations of the theory. We discuss the
applicability of Newmann-Janis algorithm to nonlocal gravity by comparing slow
rotation limit of the metric obtained through Newmann-Janis algorithm with
slowly rotating solution of the field equation.
