Give me suggestions about diet plan and exercise to increase my muscle size and strength. i noticed only small development in 6 months of gymming.

See below: Decrease processed carbohydrates, such as bread, pasta, cookies, and so on. Eat well balanced meals, including healthy carbs, fats, and proteins. Drink water. Do weight intensive exercises with your major muscles, working to do each set to exhaustion. One or two sets, six to eight reps each, once or twice a week, so show excellent results in two months. You may not be using heavy enough weights.