If there is a case of TB in a school, they will not tell you what class, or age due to student confidentiality. I'm sure that it would be helpful for parents to know where the infection is, since this is spread by coughing.
If I knew that there was TB in my child’s school, I would send them to school wearing a surgical mask. There is no reason to expose your child to an infectious disease. That’s like the parents who used expose their kids to measles, mumps, or chicken pox and then have their kid be the one with permanent damage, like loss of hearing.
The school should have a protocol developed by epidemiologists. It may not include you knowing who the original case is, but it would act to isolate those who have contact with that person and initiate testing and if necessary medication.