SATs too late for college?

I took my SATs in January and enrolled at a university in Fall of the same year (and got a scholarship because of my great scores and other academic stuff).

That said, it was not an Ivy League school (it was an above average public school). Ivy League schools really want you to apply before December or even earlier in your senior year. That might still give you an opportunity to take your SATs in early Fall and get the scores to the college before December, but I'm not sure. You'd have to look at the Fall schedule for taking SATs and at how long it takes to get your results back after taking the test to see if that works.

Is your brother's graduation during the day?? My high school graduation was in the evening... so if that's the case you could both take the SAT and go to his graduation.