Hi, CAT exams are held in the month of November. So, you have a year to get yourself prepared. Working professional usually work from 9-5 or 10-6. If you can give 5-6 hours daily just to study and prepare for CAT you can be fully prepared within 4 months. PGDM requires a lot of preparation too. If you can manage than you are good to go. If you still have doubts feel free to comment. Hope this helps.