Hi
Neo94First of all, congrats for your superb score!
You're in a very similar situation as me, although my IR score is even worse (only a 4).
I actually phoned the AdComs of some Top Business Schools (in Europe) and asked them. All of them told me that it's basically
impossible that an applicant gets rejected because of a low IR score, in combination with a very strong overall score. Schools that accept the GRE in particular won't look at IR that much, since the GRE doesn't contain such a section and all applicants have to be evaluated by the same standards.
The GMAT is only one (small) part of your application and the IR score even a smaller part of that part. So don't worry about your score and focus on the other elements of your application - you won't get an offer with a strong GMAT only.
Regarding your scholarship question: University grades, personal statements/motivation letters and your professional as well as non-professional background will be
much more important for getting scholarships than improving your GMAT score by 20 Points. Hence, spend your time on writing strong essays and letters of motivation and forget about GMAT.