What are all package needs to install to get output from Cisco router using YDK

• In our Cisco XR router (version 6.1.31) enabled below configurations 
• netconf-yang agent ssh
•   ssh server netconf
• We are executing python script to get the output using YDK models.
• Some of the features/protocols we are not getting output and getting none value .
• Hence what are the packages needs to install in the Cisco router to support Ydk model .
• Is there any package like "CSCvc57253" needs to install for supporting YDK . In our router only below CSSvc57253 installed package exists.
• "ncs5500-bgp-1.1.0.4-r613113I.CSCvc57253"
• We are not getting output for ISIS . Hence simalary do we need to install any package like CSCvc for ISIS also 

As a general rule, you want to use a version of ydk-models-cisco-ios-xr that matches or exceeds the version you're running on your router.  That package is generated form the models implemented by XR devices.  There is no additional software that needs to be installed on the router.  If you're having issues getting ISIS oper data, please share your script and its log.   You may want to be aware of a couple of defects on the XR implementation of the model: 

CSCva02506    IS-IS oper data includes unexpected duplicate values

CSCvd82599    YPYModelError: Value 0 already in leaf-list: te_ext_admin_sub

Those defects will cause validation of the operational data to fail.