Hi Kabir,
Since you have just 5 days, the best advice would be to forget about your mock scores. It is not very hard to raise your score from a 650 to a 700. I have seen many students do it and so can you.
In the last few days, make sure you go through your mistakes again. If you have a
error log, go through it and try to learn lessons from the incorrect problems.
Also, solve any of the official questions that you have left in the Official Guide and Verbal review. This will give you a hang of the questions that will be tested on the test.
Here are a few things to keep in mind on the test day:
1. Do not think about the final score at any point of time.
2. Once done with a section forget about it and concentrate on the next one.
3. Take both the breaks. It helps you to freshen up.
4. Take a note of the time when you are out for break. Do not exceed the break.
5. Do not rush through the last 5 questions in the verbal sections in a bid to see your final score.
6. Make sure you complete the sections. There is a high penalty for not completing the test.