Hi I'm nearly 16 I'm 5 ft 8 . Is it still possible for me to increase height and if so what is the fastest way?

Let me tell you that being too 'high' in a way is not so good. Your heart has to be stronger for pumping blood up to your brain. However, if you really want to grow higher, you can try doing 'bar-fix'. I don't know if you know what I mean, I'll explain. You have a fixed horizontal bar, about 1.7 to 2 metres high (6 to 7 ft) and pull your body up several times. This will muscle up your arms and make you 'longer' as well with the long run.

Hope it helped! :)

What is wrong with being 5'8 ? Are you going out for the basketball team? Are you a sprinter?