Hi Praveen,
A little clarifications here. From UIM you can configure a Spectrum Global Collection, and UIM will only get the models from Spectrum which is under this Global Collection. So this is the synchronization from Spectrum to UIM.
From UIM to Spectrum, basically if you have selected VMware Management and Server Management from the UIM Integration page, Spectrum will get all the hosts and VMs from UIM.
The attribute "User Tag" you have mentioned is an alarm attribute which comes with an UIM alarm. When you open OneClick console, go to Alarm Table, right click and open Table Preferences, you can select UIM User Tag 1 and UIM User Tag 2. Then you can see the value of these User Tags of alarms.
Please let us know if this has answered your question.
Thanks.
Yan