Mahanta is a 2007-batch IPS officer of the Assam cadre who has risen steadily through the ranks. He was promoted from Kamrup Superintendent of Police to Deputy Inspector General, went on to serve as Joint Commissioner in Guwahati and as IGP, and has led the Guwahati Police Commissionerate since 31 December 2024. He also holds the post of Inspector General of the Assam Police Special Task Force.