Hello - my son went to Lawrenceville. He had plenty of peers with SSAT scores in the 80th and 70th percentile. These scores would be fairly typical for international students with less access to English teachers, and for athletes.
I think your score will be examined closely. If there is another opportunity to take it, then do so. The decisions come out March 10, and then the waitlist starts. So if you can raise your score it might help later.
The bigger factor on whether or not you are admitted is financial aid. Do your parents need financial aid ?