I deleted time machine off my computer. Can I reinstall it?

Time Machine itself is part of macOS and cannot be deleted.

Are you having trouble using Time Machine? Perhaps If you can't back up or restore your Mac using Time Machine - Apple Support will help.

As John notes, Time Machine is software, a part of the Mac operating system which cannot be deleted.

You might have a Time Capsule, which is hardware, that you were using to store backups of your Mac using Time Machine and meant to say that you deleted or erased the backup file of your Mac from the hard drive on the Time Capsule. Is that a possibility?

If you could provide a few more details, it would help us figure out where best to start to get things going again.