You child has been prescribed antibiotics and antifever medications. Did you doctor suggest about the cause of fever - sore throat/tonsil
infection or chest infection? For any of these infections, the medications given seem appropriate.
Dengue is currently endemic in most parts of India. Best way to diagnose Dengue will be a blood test
(NS1 antigen testing). Along with that, CBC (Complete blood count
) will also need to be done.
I would advise to get him checkover by Pediatrician
and get this blood test done since fever has been persistent along with other symptoms.