According to your height your ideal body weight should be 67 kgs .a proper diet with a proper physical activity will help you with weight gain try having a high calorie high protein diet that can include fruit milkshake like banana, mango etc, fruit juice, try having dryfruits and mixed seeds, granola bars, a healthy breakfast consisting of egg whites (if non veg) or paneer corn cheese sandwich with brown bread slice. Small frequent meals at regular intervals is necessary include 6-7 calorie dense meals in a day physical exercise can include weight training exercise that will support the diet also for more information and sustainable diet plan contact us.