Why would a 12 year old be going to a college dorm?
But, there are rails you can buy to attach to the bed if really necessarily. I would first talk to your child about it as he may not want them, or may even fear being bullied for them as the other roommates most likely won’t have them.
Here’s a link from one off amazon
Safety Rail Guard for Beds and Bunk Beds 1006 by Palace Imports, Java, 14.75"H x 42.75"W, 2"x 2" Posts https://www.amazon.com/dp/B008QEVQI2/ref=cm_sw_r_cp_api_i_pIEpEb91BQVKP