I have always believed that Better Revision Better Result . So an effective revision will greatly improve your score. You can increase your speed and efficacy of revision by following some tricks -
For each time you revise try to find out the topics you forget frequently or find difficult to learn. Mark those topics and next time revise only those topics. This will greatly increase your efficacy and speed of revision.
Many students think that they will start the revision after completing their syllabus, but this is a myth. Revision is a continuous process . There is no prefect time for revision. You should dedicate 30 - 40% of your daily study time to revision.
At this time, when there is only 3 months left for exam you should increase the duration and frequency of Revision. Now your major time should be dedicated towards Revision. Focus on new and weak topics in the remaining time.
There is also a myth about frequency of revisions. You don’t need to revise a topic 20 - 30 times. Revise as many times as you find sufficient for yourself. Some topics may take more no. of revisions as compared to other topics.
So, focus on your Revision and you will feel confident and will see improvement in your performance.
All The Best !