Is it possible to get mdr TB during 5th month of TB lymphadenitis treatment? TB lymph node has enlarged. Fnac report says its secondary infection.

MDR TB. It would be very unusual to develop MDR Mycobacteria during a course of treatment. Most people with this condition become infected initially with MDR strains of this organism. Don't know where you are in Indiana, but most areas of the state have outstanding infectious diseases experts and would consult with one. Best wishes.