How many months will require to treat panic disorder..?, i've already been on medication with paroxetine 12.5 md nd clonazepam 0.5 mg..?

Varies, but 4-6 wks: Many say it works quickly, but some of that is likely to be placebo effect. Each person may have a different reaction but many describe 4-6 weeks as a time frame to evaluate it. Changes in dose can also hit the target. Work with your doctor over the next months. Also, consider cbt psychotherapy as a way to learn skills that will help for other concerns too. Good luck!