You are having extra pulmonary TB and medication for the same should at least be taken for 9 months. Irrespective of biopsy report or montoux report. You shiuld take AKT3 for next 6 months. TB is a very tideous disease and without long term treatment there is 80% chances of relapse. If relapse occurs then it is very difficult to treat and number of medicines increase along with a course of injection for 2 months. Therefore i would advice that its better to take the medicine for total of 9 months instead of taking it again for another 6 months in a painful way. These modern medicines are very potent and effective. Cure rate is 99%. So you do not need to worry if you are cured or not. Simple complete the whole course duration