Can a Mechanical Engineering become a pilot?
You have to study and write some examinations to become a pilot. Any flying school that you join, will teach you all that is necessary to 'pass' the examinations conducted by the regulator. Most of them will also have well-equipped libraries where you can read and understand a bit more than what is necessary to know. That would help you score a bit higher marks in the examinations and those higher marks could be some added advantage when an airline tries to recruit pilots. If you think of doing these studies along with your studies for your B.Tech, you are likely to be over burdened and will fail to do justice to either of your studies!
Your expenses involved is often stated as a standard package by most flight schools and should be in the range of between 25 to 35 lakhs for getting you ready for the license. Passing the examinations is your problem. If you happen to fail in one or two papers, you can reappear only after a minimum of three months for the same paper.
Secondly, the attitude of most airlines as well as private companies is that they want to hire only guys who are qualified on the model of airplanes that they are flying and also with maximum flying experience on some aircraft models. So, it is Okay to take up any flying job that comes your way after you get the license even if the pay might appear to be low - at least you gain hours on your log book and keep in current flying practice. And, based on the requirements projected by airlines, you might be required to do some flying on 'simulators' of the model they are flying at the authorised simulator flight centers. You can expect a cost of about half a lakh in Indian rupees for an hour of such flying.
Please understand that unlike a driving license, a pilot license is valid only on one model of plane at a time. And, there are some minimum flying hours specified (10 hours in the past year or something like that) to keep your license valid and current. If you get a qualification on a new model and are currently in flying practice on that model, your earlier qualifications on other planes are 'frozen' or invalid. If you want to go and fly that airplane (on which you were qualified earlier) again, you have to do some supervised flights with a qualified instructor.