The concept of a low-cost airline was pioneered in India by Air Deccan but went extinct along with the airline. Instead, what we now have are “low fare” carriers that bear little resemblance to what a low cost airline actually is.
Low-cost carriers are typified by the likes of Ryanair and EasyJet of U.K. and Southwest Airlines of the U.S. These airlines assure you of transport from City A to City B in the safest possible manner, on time and at the lowest possible cost but little else. They don't offer any of the frills of their full service counterparts.
Apart from paying for food and beverages on board, passengers have to pay for baggage that they may check in and they also have to pay for seat preferences. For instance, Ryanair, which offers the lowest fares in Europe, has a host of fees for add-ons. It charges £10 for selecting your seat, £5 for priority boarding, £15 for the first checked-in bag and £20 for the second one. The fee for checked-in bags increase during what it calls as “high season”! Southwest in the U.S. charges passengers $10 for priority boarding and seat selection. Other U.S. airlines charge up to $25 for checked-in baggage. This is not the case with low-cost carriers in India who accept checked-in baggage for free and also don't charge passengers for their choice of seats.
India also lacks the eco-system that can sustain low-cost carriers. In the U.S. and U.K., low-cost carriers fly out of smaller airports that may not be located in the heart of the city. For instance, Ryanair and EasyJet fly out of London's Luton and Stansted airports which are located far away from the city. These airports do not boast of fancy shops and other creature comforts but importantly, they charge airlines a considerably lower fee for landing and parking.
Similarly, fuel price is the same for all carriers in India. The only relaxation is when the aircraft in question is a turbo-prop in which case fuel is cheaper. Again, airport fees are low only in the smaller towns of the hinterland.
So, what “low-cost” airlines are we talking about in India?