Please tell how much cardio and working out should i do to get a flat stomach in one month?

Diet trumps exercise: Exercise will get you 20% and diet will get you 80% of the way to your goal.

There's no such : Hing as natural spot fat loss. You need to lose weight in general ; a certain % will be abdominal fat. Eat healthfully ; be physically active. Calories burned must > calories consumed. To tighten ab's do crunches, reverse crunches, exercise ball crunches, pelvic thrusts, lying leg raises, side bridge ; “bicycling” exercise on your back. Engage in regular aerobic exercise.