I'm in high school, so our schools may have different restrictions, but as long as I have my Tamas on silent I'm allowed to have them on my person, and even on my desk. I even had a few teachers point them out positively. Then again, I only have re-releases of Gen 1s and Gen 2s, so I just kind of subtly have them on a necklace that I check about every 30 minutes.
Do you know if yours has a silence option? Or maybe you could tend to it during lunch?
Btw not at ALL trying to encourage sneaking it to school. I'm simply providing what I do