Section 50(8)(k) in The Delhi Metro Airport Express Line, General Rules, 2010
(k)the train operator and the assisting metro staff at the safe evacuation point or vehicle shall check their respective count of passenger's numbers and satisfy themselves that all passengers have reached the safe evacuation point or vehicle and report the same to traffic controller, the train operator shall, thereafter, return to his train, secure the end door and seek further, instructions from traffic controller;