linux + cant installed the package GNOME Desktop Environment on linux red-hat

I have been installed the package GNOME Desktop Environment on my red-hat machine version 6.4

in the end of the installation I get the error about missing RPM- GPG-KEY-oracle directory !!!

    [Errno 14] Could not open/read file:///etc/pki/rpm-gpg/RPM-  GPG-KEY-oracle

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please advice what the resolution for this problem?

[root@MY_BABY ~]#  yum groupinstall "X Window System" "GNOME Desktop Environment"
Loaded plugins: product-id, security, subscription-manager
This system is receiving updates from Red Hat Subscription Management.
ol6_UEK_latest                    | 1.2 kB     00:00
ol6_latest                        | 1.4 kB     00:00
rhel-6-server-rpms                | 3.7 kB     00:00
rhel-6-server-rpms/primary_db     |  30 MB     00:07   

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---------------------------------------------------------------------------------------    ---------------------------------------------

                                                                                           1.8 MB/s |  34 MB     00:18     
warning: rpmts_HdrFromFdno: Header V3 RSA/SHA256 Signature, key ID ec551f03: NOKEY
Retrieving key from file:///etc/pki/rpm-gpg/RPM-GPG-KEY-oracle


GPG key retrieval failed: [Errno 14] Could not open/read file:///etc/pki/rpm-gpg/RPM-  GPG-KEY-oracle