4 months old baby 5.200 wight it's normal or low wight mam. then how to increase baby wight

A. Hai good evening !! Babies gain 400-900 gm per month,by 5-6 months they double their birth weight. Here baby weight is fine according to age no need to worry. Breast milk or formula milk every two hours ,14-18 hours sleep a day is must. From 6 month onwards start semi solids foods once or twice a day along with milk .