You should consult a pediatrician or pulmonologist. It is likely to be asthma. You can get the TB test done at any good hospital, the basic screening can be done with just a sputum test and chest X-ray, which can be done anywhere. You can ask your pediatrician if he suspects TB to order the test for you, but it unlikely to be TB from this history.
Next Steps
Consult pediatrician/pulmonologist