I'm not sure there is anything we need to do in anaconda directly for this as we just use yum.  Maybe the yum team has a better idea.

*** Bug 1217470 has been marked as a duplicate of this bug. ***

This is probably duplicate of bug 1073484 closed as WONTFIX and probably also bug 1358927.

*** Bug 1358927 has been marked as a duplicate of this bug. ***

Some of the groups are marked as hidden by design.  In order to show them, you have to supply the "hidden" keyword after the command, e.g. "yum group summary hidden".  Does that solve the issue for you?

(I presume you meant the "group summary" subcommand as there's no "group status" subcommand).

I'm usually using

# yum group list
Loaded plugins: enabled_repos_upload, package_upload, product-id, search-
              : disabled-repos, subscription-manager, versionlock
Available Environment Groups:
   Minimal Install
   Infrastructure Server
   File and Print Server
   Basic Web Server
   Virtualization Host
   Server with GUI
Available Groups:
   Compatibility Libraries
   Console Internet Tools
   Development Tools
   Graphical Administration Tools
   Legacy UNIX Compatibility
   Scientific Support
   Security Tools
   Smart Card Support
   System Administration Tools
   System Management
Done
Uploading Enabled Repositories Report
Loaded plugins: product-id, subscription-manager, versionlock
# 

When the system was installed I selected "Minimal Install" as my environment and selected "System Management" as well as "System Administration Tools".

And what about "yum group list hidden" then?  Can you please share the output?

# yum group list hidden
Loaded plugins: enabled_repos_upload, package_upload, product-id, search-
              : disabled-repos, subscription-manager, versionlock
Available Environment Groups:
   Minimal Install
   Infrastructure Server
   File and Print Server
   Basic Web Server
   Virtualization Host
   Server with GUI
Available Groups:
   Additional Development
   Anaconda Tools
   Backup Client
   Backup Server
   Base
   Common NetworkManager submodules
   Compatibility Libraries
   Conflicts (Server)
   Console Internet Tools
   Core
   DNS Name Server
   Debugging Tools
   Desktop Debugging and Performance Tools
   Development Tools
   Dial-up Networking Support
   Directory Client
   Directory Server
   E-mail Server
   Emacs
   FTP Server
   File and Storage Server
   Fonts
   GNOME
   GNOME Applications
   Graphical Administration Tools
   Graphics Creation Tools
   Guest Agents
   Guest Desktop Agents
   Hardware Monitoring Utilities
   Hyper-v platform specific packages
   Identity Management Server
   Infiniband Support
   Input Methods
   Internet Browser
   Java Platform
   KDE
   KVM platform specific packages
   Large Systems Performance
   Legacy UNIX Compatibility
   Legacy X Window System Compatibility
   Load Balancer
   Mainframe Access
   MariaDB Database Client
   MariaDB Database Server
   Multimedia
   Network File System Client
   Network Infrastructure Server
   Networking Tools
   PHP Support
   Performance Tools
   Perl Support
   Perl for Web
   Platform Development
   PostgreSQL Database Client
   PostgreSQL Database Server
   Print Server
   Printing Client
   Python
   Red Hat Enterprise Linux Server product core
   Remote Desktop Clients
   Remote Management for Linux
   Ruby Support
   Scientific Support
   Security Tools
   Smart Card Support
   System Administration Tools
   System Management
   Technical Writing
   VMware platform specific packages
   Virtualization Client
   Virtualization Hypervisor
   Virtualization Platform
   Virtualization Tools
   Web Server
   Web Servlet Engine
   X Window System
Done
Uploading Enabled Repositories Report
Loaded plugins: product-id, subscription-manager, versionlock

Thanks, that indeed looks weird.  Can you please take a look at the actual comps files in the yum cache:

  # find /var/cache/yum/ -name "*comps*"

and make sure they contain some data under the <comps> tag?

# find /var/cache/yum/ -name "*comps*" -ls
218104333  856 -rw-r--r--   1 root     root       875637 Sep 20 09:57 /var/cache/yum/x86_64/7Server/rhel-7-server-rpms/0a360c690e9443d3e5b46edb63881eb6cee775ec-comps.xml
# head /var/cache/yum/x86_64/7Server/rhel-7-server-rpms/0a360c690e9443d3e5b46edb63881eb6cee775ec-comps.xml
<?xml version="1.0" encoding="UTF-8"?>
    <comps>
        <category>
            <id>databases</id>
            <display_order>35</display_order>
            <name>Databases</name>
            <name xml:lang="as" >ডাটাবেইচসমূহ</name>
            <name xml:lang="bn" >ডাটাবেস</name>
            <name xml:lang="bn_IN" >ডাটাবেস</name>
            <name xml:lang="cs" >Databáze</name>
#

So far so good.  What about:
  # yum group info Core

That is one group that actually should be installed by default.

# yum group info Core
Loaded plugins: enabled_repos_upload, package_upload, product-id, search-
              : disabled-repos, subscription-manager, versionlock

Group: Core
 Group-Id: core
 Description: Smallest possible installation.
 Mandatory Packages:
   =Red_Hat_Enterprise_Linux-Release_Notes-7-en-US
   =audit
   =basesystem
   =bash
   =btrfs-progs
   =coreutils
   =cronie
   =curl
   =dhclient
   =e2fsprogs
   =filesystem
   =firewalld
   =glibc
   =hostname
   =initscripts
   =iproute
   =iprutils
   =iptables
   =iputils
   =irqbalance
   =kbd
   =kexec-tools
   =less
   =man-db
   =ncurses
   =openssh-clients
   =openssh-server
   =parted
   =passwd
   =plymouth
   =policycoreutils
   =procps-ng
   =redhat-support-tool
   =rootfiles
   =rpm
   =rsyslog
   =selinux-policy-targeted
   =setup
   =shadow-utils
   =subscription-manager
   =sudo
   =systemd
   =tar
   =tuned
   =util-linux
   =vim-minimal
   =xfsprogs
   =yum
 Default Packages:
   =NetworkManager
   =NetworkManager-team
   =NetworkManager-tui
   =aic94xx-firmware
   =alsa-firmware
   =biosdevname
   =dracut-config-rescue
   =ivtv-firmware
   =iwl100-firmware
   =iwl1000-firmware
   =iwl105-firmware
   =iwl135-firmware
   =iwl2000-firmware
   =iwl2030-firmware
   =iwl3160-firmware
   =iwl3945-firmware
   =iwl4965-firmware
   =iwl5000-firmware
   =iwl5150-firmware
   =iwl6000-firmware
   =iwl6000g2a-firmware
   =iwl6000g2b-firmware
   =iwl6050-firmware
   =iwl7260-firmware
   =iwl7265-firmware
   =kernel-tools
   =libsysfs
   =linux-firmware
   =lshw
   =microcode_ctl
   =postfix
   =sg3_utils
   =sg3_utils-libs
   =yum-rhn-plugin
 Optional Packages:
   dracut-config-generic
   dracut-fips
   dracut-fips-aesni
   dracut-network
   initial-setup
   openssh-keycat
   rdma-core
   selinux-policy-mls
   tboot
 Conditional Packages:
   =NetworkManager-config-server
Uploading Enabled Repositories Report
Loaded plugins: product-id, subscription-manager, versionlock

A bit silly, but are you sure you ran "yum group mark convert" instead of "yum group mark-convert" from Comment 0?

Ahhh yum group mark convert does get the group list right.

I guess it is a bit late in the RHEL6 game to get anaconda do that automatically...

Glad it helped!  I'll close this bug then.

> I guess it is a bit late in the RHEL6 game to get anaconda do that
> automatically...

Yeah, this has been discussed in the past.  In a nutshell, there's no straightforward way of having this done OOTB on a freshly installed system because there are no repos until it's registered with subscription-manager.  For more details, see:
https://bugzilla.redhat.com/show_bug.cgi?id=1073484#c13

Thanks!