The Red Hat Enterprise Linux 6 to Red Hat Enterprise Linux 7 in-place upgrade utilities, namely the Preupgrade Assistant and the Red Hat Upgrade Tool, will continue to provide a pathway to upgrade to Red Hat Enterprise Linux 7.6. The benefit of using Red Hat Enterprise Linux 7.6 as a target version is that it allows us to provide an automated upgrade experience to Red Hat Enterprise Linux 8 through the in-place upgrade tooling.
Here are the recommended configurations:

  1) If you plan to upgrade to Red Hat Enterprise Linux 8 or stay on Red Hat Enterprise Linux 7.6, after upgrading to Red Hat Enterprise Linux 7:

     - run `subscription-manager release --set 7.6`
     - enable the Red Hat Enterprise Linux 7 Extended Update Support (EUS) repositories to receive latest updates for Red Hat Enterprise Linux 7.6

  2) If yo do not plan to upgrade to Red Hat Enterprise Linux 8 or stay on Red Hat Enterprise Linux 7.6, after upgrading to Red Hat Enterprise Linux 7:

     - leave the release unset (the default) and receive content for Red Hat Enterprise Linux 7.7 or any later minor version from yum
     - running `yum update` will allow you to update the system to Red Hat Enterprise Linux 7.7 or any later minor version

Note: An automated upgrade path from Red Hat Enterprise Linux 7 to Red Hat Enterprise Linux 8 will not be enabled from each Red Hat Enterprise Linux 7 minor version. The current plan is to support an automated upgrade from Red Hat Enterprise Linux 7.6 to Red Hat Enterprise Linux 8 and from the last Red Hat Enterprise Linux 7 minor version that Red Hat releases.

For the latest information about upgrades of Red Hat Enterprise Linux 7 to Red Hat Enterprise Linux 8, please refer to:
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/upgrading_to_rhel_8/index.
