you do not say how old you are but I assume you are at the age where you can expect to still grow. While it varies from person to person, some men continue to grow in height even to the age of 21. Unfortunately, there is little you can do to accelerate this.
On the other hand, you can certainly work on your posture and try to stand as upright as you can. Slouching and poor posture can make people appear shorter than they really are, and the opposite is true as well.