Hi abimuktheeswaran Chidambaram, I can imagine how annoying this feels trying to delete a folder and running into hidden technical rules like hard links is frustrating especially when you just want to free up space.
Before deleting the $hardlinkbackup folder confirm it’s just a snapshot from a hard link backup tool and not the last copy of your files. Use fsutil hardlink list on a sample file to check other links close any apps locking files then delete via File Explorer or rmdir /S /Q after fixing permissions. If deletion fails try Safe Mode or stop the backup service.
Do you know which backup tool created the $hardlinkbackup folder and have you checked if its files are still linked elsewhere using fsutil hardlink list?
Best regards
Lucky