Could you please recommend me some good diet or plan !!

Hiya, So here's my advice, I am not a doctor by any means, however what I am going to tell you is what my pediatrician told me to get my daughter to gain weight, and yes, exercise is important because when you build lean muscle mass it weighs more than fat. However, it also burns calories, ie fat, and can have the opposite effect and isn't the best advice from your doctor, (in my opinion.) The fact that you are a vegetarian is not a problem at all, there are a lot of healthy fats that you can get from other sources besides meat. Since you drink milk I am guessing dairy is part of your diet, & milk, eggs, yogurt, cheese are all good sources of healthy fats. You should try eating 30 mins after you wake up, and breakfast should contain a lot of carbs. My daughter had avocado at almost every meal, high in good fat. If you like fish, Mackerel, Herring, and Salmon are the fattier of fish, (healthy fat) at about 200 calories per 3 ounce portion, vs. Flounder, Cod, & Sole, which only have about 100 calories or less per 3 ounce portion. A protein shake (you can find at health food stores) blended with peanut butter, as a snack in between meals is a good way to put on weight. You should be eating at least 5 times a day, and whole grain pasta should be incorporated into two of them. If you have dairy in all of your meals, and your two snacks, carbs in all three of your meals, a protein shake every day and fish 2-3 times a week, you should start to gain weight. I hope this has been helpful. Good luck! 

Hi - Thank you very much for your kind advice . I already started this routine . I hope it will work . : ) Regards