Access control of the Aircraft is the responsibility of

In accordance with the National Civil Aviation Security Programme (NCASP) and guidelines issued by the Bureau of Civil Aviation Security (BCAS) in India, the responsibility for the security and access control of an aircraft rests with the Aircraft Operator (the airline). While the Aviation Security Group (ASG), typically the CISF, is responsible for the overall security of the airport terminal, perimeter, and passenger screening, the airline is specifically mandated to ensure that no unauthorized person gains access to their aircraft. This includes guarding the aircraft while it is parked on the apron and verifying the credentials of all personnel (cleaning staff, catering, etc.) and passengers entering the aircraft.