I am 20 years old , and im doing streching for 6 months , i was 175 , and now im 181 , how did that hapend , ? if i countinued , would i grow more ?

Stretching and weigh: Stretching is good but it won't help you lose weight if that's what you are concerned about. Aerobic exercises that will increase your heart rate to about 120-140 beats per minutes with a health diet will help you lose weight. Stretching is good to keep your muscles in shape - no more !

Growth Hormone: Males grow til they are 20...So good job. You may grow more...I am not sure how much the stretching helped but cannot tell you it did not. Generally your final height will be relative to your tallest family member...If there are males 181 cm then you are in the range...