I need to ask few more questions before answering your query. Early consultations can prevent complications. Kindly contact me on whatsapp chat  (84960595 six five) Dr Faisal Zoheb MBBS , MD PAEDIATRICS , PGPN (BOSTON), FELLOWSHIP IN NEONATOLOGY ( Newborn and vaccination specialist )

Greetings It is concerning that your child has not gained weight for a year and has red spots in his mouth, which could be consistent with vitamin deficiencies, hand-foot-and-mouth disease, or an infection like tuberculosis (TB). Children in close contact with an adult who has active TB are at high risk of infection, which can cause poor weight gain and requires urgent evaluation. You should take him to a pediatrician immediately for a TB skin test (Mantoux) or blood test and a chest X-ray.

Weight of 12 kg at 2 years 9 months may still be within acceptable range depending on height and previous growth curve, but if there is truly no weight gain for long duration, evaluation is needed. As there is close TB contact at home, it is advisable to get your child examined by a pediatrician once for TB screening if needed (history, examination ± Mantoux/chest X-ray as advised). Red spots/mouth ulcers can occur due to many causes including viral infection, nutritional deficiency etc. and are not specific for TB. Do not panic, but since there is close contact history plus concern about poor weight gain, proper pediatric evaluation is recommended.

Consult with Pediatrician physically for further evaluation and treatment

Yes urgently do TB test

Weight is appropriate Dont worry .shld b between 12-13 kgs . Give multivitamin syrup If ur grand father is on treatment no need to worry . but maintain distance child with ur grand father until his tb smear is negative .