Is it normal for a child 6 yrs with tonsillitis infection to have fever for 5 days. he is taking antibiotics and fever reliever. ?

Yes: The most common reason of tonsillitis is viral. So the possibility of this is most likely viral. Antibiotics is of no use.

Hello: It is fairly common to see a child suffering with tonsillitis to maintain a fever while on abx and analgesics. Things that could account for the persistent fever may be fluid intake, possibly a resistant bacteria or the development of an abscess. See your family doctor for continued care.