Greetings and complements for caring for your baby. As for wt is concerned it doubles in 5-6 months of age.observation  is 6months. So relax. It is human body and not a machine. It is range of growth.  So Relax. He will grow and put on weight..other parameters are normal..lt depends on food , activity , ventillation, exposure to Sun and very important issue positive happy healthy emotional environments. Peace and happiness prevellance. No arguments, discussions or shouting or abuses. It is noticed that that surroundings, they respond by behavior problem. Search yourself out of above points. Nutrition has to have enough energy- calories with vitamins mineral, antioxidents.  Look for loophole in your diet. And correct . Activity increases appetite. Ventillation give you more oxygen.essentional for all systems  Sun imoroves circulation and stimulates viaminD production by sink Check whether enough proteins are given around 1gm per kg weight. Veg give you minrals and antioxidants.Fruit does same thing and stimulate taste. My dear friend , I have given you a jist.  Bring a change in your schedule. Prevent infection by observing Hygiene. Prevent Mosquito menance to prevent .Malaria, dengue and filaria. Any of infection will halt growth. DON'T forget immunization

Greetings, his weight is adequate for his age , continue only with breast feeding, start solid food only after 6months .