The GeoIP feed provides an up-to-date mapping of IP addresses to geographical regions. This gives you the ability to filter traffic to and from specific geographies in the world. 

This article explains a reason why a device that is enrolled in ATP cloud and configured properly might not be receiving the GeoIP feed. 

user@srx> show security dynamic-address summary 

... 
Instance Name                                  : geoip   
    Total number of IPv4 entries               : 0    
    Total number of IPv6 entries               : 0       

If the device is enrolled to ATP cloud but does not have a license, the cloud connections might be successful but the GeoIP feed will not be retrieved.

For GeoIP feed to work, the device must have either an ATP "premium" or "advanced" (threat feeds) license.  Acquire an ATP license for the device and activate it in the license portal.  

Related info:

Configure Juniper ATP Cloud with Geolocation IP

Complete list of current officially-assigned ISO 3166-1 alpha-2 codes 

https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2