For six pack abs, start by losing overall body fat. You cannot lose fat on your stomach by doing ab exercises alone.

One part of getting a six pack abs is to reduce fat on the stomach which is covering your abs. However, the body can't be forced to lose fat in a particular area by exercising the muscles directly under that area. Cardiovascular exercises like running, cycling, brisk walking, swimming, etc are the best exercises to burn fat. You can start with 15 minute a day cardio exercise for 3 to 5 days a week and increase it to 45 minutes for the best result.