Not able to update the system even when system is properly registered and subscribed

Issue

• Yum command show below output:-

# yum clean all
Loaded plugins: product-id, search-disabled-repos, subscription-manager
There are no enabled repos.
 Run "yum repolist all" to see the repos you have.
 To enable Red Hat Subscription Management repositories:
     subscription-manager repos --enable <repo>
 To enable custom repositories:
     yum-config-manager --enable <repo>

# yum repolist -v
Not loading "rhnplugin" plugin, as it is disabled
Loading "product-id" plugin
Loading "search-disabled-repos" plugin
Loading "subscription-manager" plugin
Updating Subscription Management repositories.
Config time: 0.365
Yum version: 3.4.3
Setting up Package Sacks
repolist: 0