The National Investigation Agency (NIA) is a federal agency responsible for the investigation and prosecution of acts of terrorism and other national security-related crimes in India. Here are some of the ways in which the NIA is investigating the attacks on Indian Missions in the U.S. and Canada:

• The NIA is gathering and analyzing intelligence related to the attacks, particularly with respect to the individuals and groups involved.
• The agency is working closely with law enforcement agencies and other stakeholders in the U.S. and Canada to get a comprehensive picture of the attacks and the actors behind them.
• The NIA is also working with the Ministry of External Affairs (MEA) and other Indian government agencies to determine the motive behind the attacks and the potential implications for India's diplomatic efforts in these countries.
• The agency is using advanced technologies and investigative techniques, such as forensic analysis, to collect and analyze evidence related to the attacks.
• The NIA is also liaising with its counterparts in other countries to gather intelligence and collaborate on investigations related to the attacks.

Overall, the NIA is playing a critical role in investigating the attacks on Indian Missions in the U.S. and Canada, and is working closely with other agencies and stakeholders to determine the scope and implications of these incidents.