The federal probe agency is tasked with probing terrorism and terror-financing related cases.
The Appointments Committee of the Cabinet (ACC) approved Modi's appointment as director general of the NIA, an order issued by the Department of Personnel and Training (DoPT) said.
Another senior IPS officer, Rajni Kant Misra, has been appointed director general of the Sashastra Seema Bal (SSB). Modi will hold the post till his superannuation, i.e. May 31, 2021, the order said.
ACC has also approved the appointment of Mr Modi as officer on special duty (OSD) in NIA with immediate effect to ensure a smooth takeover.
Mr Modi, a 1984 batch IPS officer of the Assam-Meghalaya cadre, is at present special director in the Central Bureau of Investigation (CBI).
Mr Kumar, who was appointed DG NIA in July 2013, has been given two extensions.
In October last year, he was given a one-year extension, apparently to help the agency complete some important probes, including the Pathankot terror case, terror strikes in Kashmir, Burdwan blast case and the Samjhauta blast cases Mr Misra has been appointed director general of the SSB till the date of his superannuation, i.e. August 31, 2019, the DoPT order said.
Mr Misra, a 1984 batch IPS officer of Uttar Pradesh cadre, is at present additional director general in the Border Security Force (BSF).