Six pack abbs requires requires a resistance training exercises and a proper proteinious diet . Resistance exercises includes the crunches, Reverse crunches, Heel touch , abbs cycling, 90* abbs crunches, etc. Do these exercises atleast for 20-30 min 5/week .Also include some of the cardio activities like Brisk walk ,Jogging, Running, Swimming, etc and try doing this exercises atleast for 30 min 6/week .Cardio activity will help reducing fat from your body and resistance exercises will help shaping up your abbs so as to get a six pack abbs. Also protein diet with least calories is really important to build muscles so diet also plays an important role to make a six pack.