Hi, you have an ideal weight according to your height. You need to take 1.5 - 2 gram protein per kg body weight to build more muscle mass. Restrict your carbohydrates and fat intake. Some dietary protein sources of food are milk, paneer, curd, soybean, sprouts, pulses, eggs, chicken, fish. So if you are 72kg , you need about 110 - 140 grams protein daily to build muscles along with your gym exercises.