Concurrent jurisdiction allows Inspecting Assistant Commissioner to exercise and direct Income-tax Officers' powers and functions. Concurrent jurisdiction allowed the Commissioner to direct the Inspecting Assistant Commissioner to exercise powers and functions of an Income-tax Officer; Income-tax Officers were required to follow directions and guidance from the Inspecting Assistant Commissioner, with a prohibition on issuing instructions prejudicial to the assessee without an opportunity to be heard, and statutory references or approval requirements adapting to the Inspecting Assistant Commissioner when he performed Income-tax Officer functions.