What are my chances of getting into MIT with a 800 in MATH 2 and 680 in physics?
Could that 800 compensate for the 680?
Nobody should hazard a chance based solely upon one small piece of the total application. But be aware that there will be many applicants who have 800’s in both.
800 in math 2 is almost expected, a 700+ for any other science is also expected.
This is for MIT
Nobody can tell you your chances, but there definitely are applicants that got excepted to MIT with test scores in the high 600’s.
The always wonderful @MITChris commonly points out that MIT likes to see the first digit on test scores to be a 7. However, also be aware that test scores are not everything. MIT is unlike any other college, in that their admissions process is very transparent. I highly suggest checking out the MIT Admissions blog: http://mitadmissions.org/blogs.
I have followed the blog almost daily for the last few months, and I can quite honestly say I have gained so much from reading them. My biggest take away is that MIT admits people, not test takers. Reading through the many blog posts, I see the students at MIT are some of the most compassionate, humble, and hardworking people around. MIT is obviously an incredibly selective school, but they factor a lot into the application.
If anything I suggest reading this blog post: http://mitadmissions.org/blogs/entry/applying_sideways
Hopefully, it will give you some encouragement during the admissions process. I can say that college applications have been completely terrifying and daunting, but in the end, we are all humans, and applications are inherently just another human interactions between two of us.
I wish you the best of luck during your application season!!!
They are also OK with the first digit being 8. 
@skieurope I mean who wouldn’t be “OK” with that haha