How can i increase my hight?

Make sure you eat healthily and get plenty of rest. That is about all you can do to make sure you grow as tall as possible. Exercise won't help you get any taller. If your parents are short, chances are you are also going to be short (sorry!). That's just basic genetics and there's nothing you can do to change that; you've got the genes you were born with and that's that. As I said in answer to this question elsewhere your maximum adult height is 1.3 times your height at 9 years old; assuming you're a boy, you'd have had to be at least 4ft 7inches at age 9 to stand any chance of ever making it to the 5'7" - 6' 0" range as an adult.