“One in four American teenagers accesses the internet primarily through mobile; about three quarters of those teens own cell phones, and half of that group uses smartphones.”

– Pew Research center via Gigaom

This number has to be higher in India. My teenage brother only accesses Internet from his smartphone and uses desktop to watch movies. This too, only because he doesn’t own a tablet yet. I am guessing once he owns a tablet he would completely give up on desktop.