How I grow taller my age is 21 year and my height 5 feet 3 inch. I waana grow tall upto 6 inch?

If you figure. That out you will be a very rich man. G-d decides your height. (if you believe in a g-d). In case you are an atheist...Then man does not get to determine his height. It is what it is.
Won't happen. The same hormonal changes that trigger puberty also signal the growth centers of long bones to close. Once they close, they do not re-open and no additional natural growth is possible.If you have lots of cash,ready to handle lots of pain and a year or two to waste, there are surgical procedures in some countries that could lengthen your leg bones.
That won't happen. At age 21, you've reached your full growth. My acquaintance, bodybuilder lee priest (photo), is 5'3". He's not complaining. Physical fitness and development in a man takes precedence over everything else when it comes to looking good. Some scientists say that shorter men live longer and age slower. Enjoy who you are.
Be Happy with 5'3" I don't think you can grow taller after age 21, you can only grow bigger , which is not adviced. Be happy with your height and stay healthy.