Time machine

Part of being able to help you is to know what your reason may be for deleting files in Time Machine.

There is a way to do it safely by entering the Time Machine application.

Unfortunately, if you do simply browse into the backups.backupdb and start deleting files that way, you will muck up the ability of TM to do what it's designed to do.

Here's a link that will give only some assistance. Please follow through with a bit more research before you take action.

https://support.apple.com/guide/mac-help/delete-a-file-time-machine-backup-disk-mh26863/mac

If you want to make a mess of Time Machine begin deleting files. Please allow TM to run normally, it will remove older backups automatically when it senses it is running low on space. Please refer to:https://support.apple.com/en-us/HT201250

If you want to delete an older backup, connect your backup drive to your computer, then go to Time Machine, find the backup you want to delete, click on the gear, and then click "Delete Backup", and confirm.

If you want to delete a specific File, connect your backup drive, go to Finder, click on your backup drive, then click on "Backups.backupdb" and within that, find your computer name folder and enter that. Then you will see the dates of different backups in subfolders. If you want to delete a certain date you can right click and "Delete" that file, (don't use the Trash, just delete) or you can navigate that date folder for the specific file you want to delete from that backup.

As rkaufmann says, don't. If for any reason TM stops deleting backups automatically only attempt it via the Time Machine interface, never in Finder. The files will always get stuck in the Trash and then you'll need to erase your TM volume and start over.