Honestly speaking 7 days is not the time where you can start with a new topic for your boards.
Last year when i was appearing my boards, these 7 days were very crucial for all sorts of practice and revision work.
Time is actually up. So now all that you can do is revise and revise and revise.
Be focused dont get tensed,tension will just worsen things more. Relax and dont over exercise your brain. Keep clam it will help you in improving your performance finally.
Dont stay awake till late night like other days,maintain a strict time table and follow it sincerely. Go to sleep early and atleast have a sound sleep of 5 to 6 hours before exams. Eat healthy and be self conscious.
These 7 days wont bring a big difference in your performance, your performance will be a reflection of you hardwork for the past year so for these 7 days prepare yourself mentally, be morally strong and expect the unexpected this way you will not be helpless when you get your paper.