How to stop "NTFS new version", or any notification for that matter? I used paragon NTFS for a while and then deleted it from applications folder. I also removed the dmg file(I know it would not stop notifications). 

But I keep getting notifications like this everyday.

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Clicking on it is useless. Safari would open(if not already) but no new window, no webpage, nothing.

I searched the Library folder for NTFS and paragon and deleted files and folders for e.g. from application support, from caches. One folder in its name had "notification". I deleted that too. Unhid hidden files by CMD + Shift + . For a temporary fix, I turned off notification from System Preferences. But I need a permanent fix.
Any App you need to actually run an installer &amp; give admin perms, rather than just drag to Applications, installs elements somewhere inside the 'system' itself.

It is not wise to just throw these out if you no longer want them, as they will leave all the system bits behind.

As you threw away the component which contains the uninstaller, the app itself, then by far the simplest way to uninstall it will be to get the installer again, install it, then use its own uninstaller to uninstall it.
At the moment it is still entirely functional, you only threw out the control surface.