They get saved as default setting.
How many versions and how much disk space (etc) are all controlled in Options under the File tab.
Labeled 'Create backup file when overwriting a SEQ file'.

Check your current active PT or RB folder (likely C:/Realband or C:/PT) for a sub-folder named RBBackup or PTBackup.

Your backup copies live there.

Currently in RB you would use File-Open Special .. then select Open Backup
In the older version of PT I was on in this instance it was File-Open Backup

I'm just glad they are there!

I do not work here, but the benefits are still awesome
Make your sound your own!