Well,
I have a question for you: Is your GMAT too low for WHAT? I mean what are your goals? Where do you want to apply? What is your work experience like? And your academic career? Everything is connected!
If you can send me some more info, I may be able to help you out,
Only GMAT cannot prove anything. If you have other extraordinarily "interesting" things, you can even be accepted by H/S/W with a 670 GMAT. However, if other parts of package are very weak, perhaps you cannot get any offers from any top 50 schools.