Your study plan should be based on your own pattern of strengths and weaknesses in each subject, allowing more review time for weaker areas and less to stronger ones. Most IMGs will need at least 4 months to prepare, so you should have enough time.
We recommend using a question bank of some kind while you are studying, both for practice and to assess your progress. You may want to divide the time you plan to spend into an initial 2/3 chunk and a final 1/3 chunk. The first is for your thorough review of each subject, with self-testing gradually increasing as you begin taking tests composed of items from ALL completed areas. The final 1/3 period is for more intense test-taking practice and remediation for weak topics in between self-testing sessions. Your testing performance should dictate when you actually take the exam, however, because what counts is only how well you can apply what you review to solving questions. I hope this is helpful. Good Luck!