Dear Sire,
i want to use user manager in my router, it can't install package user manager in my router.i use Router mikrotik os Version 6.30.4
So i can't download package this version.Please Help me, Thank Before Your hand.?

Start by updating to latest stable version, 6.36.2 as of this time. Don`t forget to go to System > Routerboard and upgrade firmware rebooting afterwards.

User manager is available for that version.