How i grow my height? i am 21 now

You're likely done: Boys and girls are typically done growing by the time of their later teen years. If you're a shaving male or menstruating female you are likely well past growth because your growth plates are fused closed.

Leg lengthening surg: At 21, your growth plates are sealed and thus vertical growth is no longer occurring. The only option at this point would be to have a leg-lengthening surgery--a gruesome procedure but can add a few inches. Keep your body proportionate/good healthy wt--good things come in small packages. If you are not happy with yourself, consult doc for eval. I am pretty sure u r taller than i. Good luck.