I am 16.5 years old and haven't grown much in the past 6 months(some mm i guess). i am 5'6.5 , my mom and dad are 5'1-5'2 and 5'7.5. i grew 3-4 cm last year. i think i have slowed down, can i grow another 1-2cm in the next 6 months?

Maybe: Your projected final height based on parental height is 5'7" plus or minus 1 inch. Future growth depends on open growth centers in you bones which can be verified by an x-ray of your wrist/hand. If closed, you are done, open would suggest more potential.The slowing you not suggests you are near the end of your linear growth.

Nearest same gender: Most children will approximate the height of their same gendered parent as an adult. Children can grow taller if their opposite gender parent is significantly taller than their same gender parent. Nutritional considerations such as protein intake and lack of disease/infections will maximize your height. Boys typically finish growing around age 17. Unknown if 1-2 cm more in the next 6 months.