It is always preferred to do Graduation in some stream be it Science, Engineering or Mathematics before you venture into becoming and training for an Airline Pilot. However, in todays date many private flying schools induct students after 12th. To become a Pilot, firstly you need a Commercial Pilot License from DGCA and respective Medical Certificates. No doubt Commercial Pilot Training will be expensive, but worthwhile and can be considered as a one time investment. Though many scholarships are available in the Commercial Training Academies, many aspirants having monetary issues may prefer joining the Indian Air Force Flying Branch through AFCAT and other Fitness and Medical Tests, Gain a strong experience of atleast 10 years and then enter the Commercial Flying Arena with a Top Airline Company directly as a Captain or Flight Commander, depending on experience.

All the information you need to become a pilot, including monetary structure are given in the link below

https://www.careers360.com/careers/airline-pilot