I am 58 male aged 17. from january of 2021 to july, i gained like 10kg. i think fat increased in my belly region, and i have 25-30% fat. but isnt 10kg too much?any reason of this happening? is my body preparing to grow taller by gaining weight?

You either put on muscle mass or fat. Ten Kg in 7 months is a bit excessive & likely just reflects overeating. I would not expect to grow much taller at your age. Most men stop around 17. If you have not grown more than 1 in in the past year you are near the end if not finished.

Weight gain is not necessary for gaining height. When you gain height, due to more muscle mass you gain some weight. Please pay attention to the food you are eating and may need moderation. Hope it helps.

Your weight gain is likely to be mostly fat. Be careful with your diet so that your BMI goes not exceed 25. Visit this site for calculating your BMI: https://www.nhlbi.nih.gov/health/educational/lose_wt/BMI/bmicalc.htm Get regular exercise.