What Are my Chances at Private School

I am currently a freshman who is applying to private school as a day student and boarding student to top schools like Andover, Choate, Lawrenceville, and others.
Here is a rundown of my application:
I was only able to take the SSAT once and got in the 70th percentile which I know is very low. I did do good in math and ok in verbal but bombed the reading comprehension for some reason.

In school, I have maintained a 4.0 grade point average. As a freshman, I am enrolled in the most challenging courses that our schools offer. I have gotten one B in 7th grade spanish, one B+ in 8th grade spanish, and a B+ in World Studies Honors which should weight to a A-. Apart from that I have gotten A’s and some A-'s.

I am very involved after school:
I volunteer teaching robotics to less fortunate kids.
I am part of my high school’s robotics team.
I am part of a physics/science competition team which plans to attend nationals in June.
I do Model United Nations.
I spend lots of time playing competitive tennis where I am ranked in the state.

I am also a boy scout at the rank of life where I hope to achieve my eagle scout ranking soon. In this, I have served many leadership positions leading my troop.

In addition, I have in past years done middle school track and cross country as well as band. I have not included these in my application because I am not currently doing it.
What are my chance? Any Tips?

As everyone will tell you, the schools you mentioned are really selective and if you really want to go to BS, you should consider adding some others to your list. Your stats are unlikely to make you stand out in a really competitive crowd. Without knowing about your private day option, we can’t comment on whether that is a good fallback.

It sounds like you are engaged in a wide range of activities (which BS like), so going to BS isn’t unrealistic at all. If you only apply to those 3 only, your odds may be slim though. Definitely reach out to the tennis coaches.