Dnt depands on buffer time...ndls-cnb have some regular fault occurring incident. Last day I met a men in metro who was travelling from cnb to Anvt by 02395 and he has to catch the flight @2 am in next morning.... Guess what??? All trains on cnb-ald route was late by avg 6 hr.... And during boarding time he was in the metro... And asking the best possible sol to reach IGI Airport. So plz ensure some plan that you will definitely reach Delhi in any situation