Can you tell me how could a 13 year old boy get six pack?

Overall fitness: You'll need to have very little body fat from diet and aerobic exercise, and also do some specific training of the abdominal muscles. This is easier to do now than at any other time in your life because of your growth spurt and increasing levels of testosterone. It would be great if dad or some other positive experienced men would be your coaches as you undertake this.

Diet/ exercise: You are most likely to have visible washboard abs or a 6 pack if you cut your body fat down to the 3-5% range. This is difficult since most kids pre-teens and teens run 15% . This would be difficult at 13, because you are still growing and any diet restriction could affect other important growth in your system.You might be able to do this safely if you work with a dietitian,but I'd wait until 18