The status of this response is Pending and require some modification by the author.
There will be sports academy to teach table tennis or similar kind of sports activity to keep up your son concentrated in sports. For online learning there are lots of Android apps which Will conduct online coaching classes About lots of topic, like coursera, udemy and Khan academy. For kids at the age from 14 to 18 it's good that they can go for fencing, archery and swimming Classes, because these classes are not only for extra curricular activities but it also increase concentration and increases brains activities than normal kids also, these kind of regular activities will make them not to accept any bad habits throughout their life. Give the kid some topic and tell him to create a project and instruct him to collect details about that topic after finishing it give some gifts that will help him in future to accept any projects that will be given to him. Don't argue or compel them to go to summer classes ask them if they are willing otherwise leave it their way and make them sleep a lot, as per surveys we know good sleep increase brains capacity to know more things and be active all the time.