Is this normal for school proms?

[FiveHoursSleep]

DD1 is now in Y11 and there is Talk of the school prom. She's at a girls' school, so it's held with the boys' school but they parents organising have booked a venue that will only allow 200 tickets to be sold.
There are over 360 Y11 pupils in the two schools so that means a lot of the kids are going to miss out.
The tickets are being sold first in, first served tomorrow lunchtime at school so it's going to be quite a ruck.
DD1 is ambivalent about going but her friends really want to, so she's going to try and get a ticket, but someone is going to miss out. I know some people won't want to go but that's a large number who won't be able to.
Is this how it's normally done?

At my DCs school all can go except those who are excluded from the prom due to bad behaviour or poor attendance caused by truancy or exclusion from school rather than illness.

That's awful! There was only about 100 of us in my year of school. Everyone had the opportunity to go. Only under extreme circumstances to do with behaviour were people banned. That's an horrible way to allocate tickets.