What do you suggest if i am 20yr old can my height be increased.?

Unlikely to happen: At twenty your growth centers have likely closed and you are unlikely to grow taller.If you want to know for sure an x-ray of your wrist &hand can be analysed for bone maturity &tell if the growth centers remain open to new growth.Good nutrition, rest and exercise allow a person to reach their tallest height while the opposite will stunt growth.