CUCM 6 does not support auto-attendant functionality itself.
Complementary products including Unity, Unity Connection and Contact Center Express can provide this but require a separate server and licenses.
You may have a five seat license for Contact Center Express already as Cisco have a promo that supplies these with CUCM but you would still need to buy a server (e.g. 7816 $4,000) and Windows OS ($2,995) to deploy it.
Windows based versions of CCM allowed you to install the contact center software co-resident with CCM but this is no longer possible with Linux based CUCM systems.
Are you getting this error “Installer User Interface Mode Not Supported. The installer cannot run in this UI mode. To specify the interface mode, use the -i command-line option, followed by the UI mode identifier. The value UI mode identifiers...
The below trick might come handy when you have to add a new node to a cluster but you don't have or is unsure of the security password for the publisher. This procedure has been around for ages.
1) Login into the CLI of the Publisher.