The National Investigation Agency (NIA) is India's premier counter-terrorism law enforcement agency, established to address and investigate offenses related to terrorism and other crimes with national significance. Formed under the NIA Act on December 31, 2008, the agency operates with a mission to create deterrence against existing and potential terrorist threats. The NIA has become a vital player in tackling various forms of terrorism, including those fueled by international networks and transnational crimes such as arms trafficking and counterfeit currency circulation.

The agency is responsible for investigating a wide range of cases, having registered 690 cases to date, with a notable conviction rate of 92.31% in the 169 cases that reached judgment. NIA collaborates with several partners and maintains a framework that includes special courts dedicated to trial proceedings for such serious offenses. Central to its operations, the NIA emphasizes public involvement, urging citizens to report suspicious activities to protect national security.