Flights from Delhi to Bangalore are quite regular. The reason is that they are in high demand being the best alternate to approach the destination on ease and no delay. Distance between the cities is approx 1750kms that takes 30-35 hours to cover by a train. On other hand, if you take a flight from Delhi, it takes around 3 hours to get into Bangalore. Charges are also reasonable, not too more than the charges of an AC first-class train fare.