Here is a Juniper device template for Junos devices. This template has been adjusted for the username of "root" specifically. If you are using different username for NCM to connect to these devices, you may have to modify this device template as it is using that username to help identify the device prompt. (<Command Name="VirtualPrompt" Value="root@"/>) These devices are a bit trickier in NCM, as the device requires you to enter a command "cli" at which point the prompt changes from "%" to ">"
--- JUNOS 12.3R6.6 built 2014-03-13 06:51:40 UTC
root@routerhostname> show configuration
Tested specifically with a Juniper MX960 running JUNOS 12.3R6.6. However it may also work with other Junos devices.