hello ,my baby boy weight is 9kgs and he is close to 6months.his birth weight was 3.3.. is this normal

A. Look if we go only as per the convention it should be somewhere around six. 6 kg to 7 kg but it is also true that where you say that the minimum gain should be 500 g to maximum again 1 kg kilo kilogram so if I look at the birthweight under current gain and this is exceptionally healthy