Hello, I'm 17 years old, I'm a boy and I'm only 155 CM height, can I still grow until 21 years old, and how much? Please answer. Thank you.

Possible. It depends on genetics and parental height, as well as your level of maturity, called Sexual Maturity Rating. Since you are under 18, you would want to share this info with your parents and discuss with them too. You have not provided a lot of info I would need to answer it fully.
YES. You can continue to grow; however, many factors are genetically programmed.