Hello! First of all tell me why you need this 6 marks? Is it very important? From my point of view I suggest applying for revaluation may or may not be favorable. You have 50% of chance to get improved score and there is another 50% of chances to get the same score even after revaluation process. But you should also consider the possibility of your scoring coming down. So better consult with your professors before applying for revaluation.

Next, I would suggest you side by side prepare for the improvement exam. But during this pandemic time, going and writing an improvement exam is not advisable. Hope this was helpful. Thank you.