All of the top schools reject tons of kids with SSAT scores in the 95th percentile and above. Once your SSAT score is at or around 85th percentile, you are in the “could handle rigorous academics” pile. That pile is NOT ranked. Whether you are accepted or not then depends on everything else in your file (essay, teacher recommendations, extracurriculars) and what they are looking for to round out that particular class (are all their violinists graduating next year? are they in the market for a lacrosse goalie because theirs is leaving for a school year abroad? etc).
Do NOT waste time trying to raise a score from teh 87th percentile to the 97th percentile. Spend that time instead polishing your essays, winning awards for your ECs, or improving your grades and recommendations from English or Math teachers.