hi, 

You want to become a playback singer then you need to learn music. If you have already learnt music and youre a senior learner in music then the best music university is of A.R rahman, which is rahman music school also known as KM Mussic conservatory. Try for that. Its a pretty awesome school for music aspirants. visit their website for more details. Their website- http://kmmc.in/

Hope it helps, 

Good Luck