1) Try for the IndiGo cadet program first. Consider training privately as the second option
2)Clear your class I medicals before investing a penny in aviation
3)With B.Tech. in mech., You stand an advantage over the rest in the Tech. Gen. paper. Not in others. (I'm an aerospace engineer from a 'reputed' college)
4)Do your own research before choosing a flight school. There are many agents around who'll be ex students of flight schools and get a commission for referring every student.
All the best