Help i need to loose wieght?

i'm 16 years old boy and i wiegh about 58 kgs and my height is 5.7 feet i know i'm bigger than normal guys and i don't look fat due to my height and i want to loose 5-6kgs.i do 50 crunches,100 push ups,100 sit ups daily night as i cannot spend my time for exercise during day.is it enough for me to reduce my weight .how long i have to continue plzz.. Help me out .