Download the appropriate Update ISOs from Red Hat Network (RHN).
Login to RHN.
Click on the ‘Channels’ tab and from the left pane click ‘Download Software’.

Select the appropriate Red Hat Enterprise Linux channel and download ISOs (Install Disc).

Mount the ISOs in a local directory on the system, for instance: $ mount iso_filename /media/cdrecorder -o loop

Copy all the RPMs from the /media/cdrecorder/RedHat/RPMS to /var/spool/up2date directory as shown below:

$ cp /media/cdrecorder/RedHat/RPMS/*.rpm /var/spool/up2date

Repeat the above steps for the remaining ISOs.

Edit /etc/sysconfig/rhn/sources file, comment the line as shown below:
# up2date default

Uncomment and modify the last line to look similar to:

dir my-favorite-rpms-i386-9 /var/spool/up2date/
and save the file.

Now, up2date the system and it will receive all the updates from the /var/spool/up2date directory.