500 grams is on the lower side. Please feed the baby longer at the breast so that baby gets fore milk and hind milk. The hind milk is more rich in fats and proteins and vitamins and other nutrients and hence important for weight gain. While feeding the baby you can also massage the breast to encourage the fat which gets stuck in the ducts to dislodge and pass to the baby.

hello seema change your diet, start eating green vegetable as well eat fruit. have healthy food ghee daliya, methi, khajoor and full glass of milk