First of all, kindly do not get influenced by any over the counter products or advertisements that claims to increase the height of an individual.
Height of an individual is determined by Genetics, Environmental & Nutritional factors and Hormonal
factors (most important the Growth Hormone
secreted by pituitary gland
An individual stops growing in height after the fusion of the Epiphyses (growth plates) of the long bones, which occurs by the age of 19-22 yrs in males.
If you want to know if the growth plates have closed or not you can get an X-Ray of your wrist and forearm done.
It'll show the growth plates and whether they are fused or still open.
Wishing you Good Health.
Thanks and take care.