Answer
You can only reactivate a Facebook account if you’ve deactivated it in the last 14 days. 14 days after deactivating your account, your account will be permanently deleted, and cannot be recovered.
How to Reactivate Facebook Account
How to Delete/ Reactivate Facebook Account On Mobile (Easy)
Can you rejoin Facebook after deleting account?
You can only reactivate a Facebook account if you’ve deactivated it in the last 14 days. 14 days after deactivating your account, your account will be permanently deleted, and cannot be recovered.