Hmm ... It's impossible ;-) This RPM doesn't exist on any FTP server

Provides :
config(xorg-x11-xdm)
libXdmGreet.so
xdm
xorg-x11-xdm
xorg-x11-xdm(x86-32)

Requires :

libXt.so.6
libXinerama.so.1
libdl.so.2(GLIBC_2.1)
libXaw.so.7
libdl.so.2
pam => 0.78-0
rtld(GNU_HASH)
libc.so.6(GLIBC_2.4)
libc.so.6(GLIBC_2.1.3)
rpmlib(PayloadIsXz) <= 5.2-1
libXpm.so.4
config(xorg-x11-xdm) = 1:1.1.6-14.1.el6
libXext.so.6
libc.so.6(GLIBC_2.0)
libdl.so.2(GLIBC_2.0)
libXdmcp.so.6
/bin/sh
libc.so.6(GLIBC_2.11)
rpmlib(PayloadFilesHavePrefix) <= 4.0-1
libc.so.6(GLIBC_2.3)
libpam.so.0(LIBPAM_1.0)
libXau.so.6
libX11.so.6
libpam.so.0
libcrypt.so.1
rpmlib(CompressedFileNames) <= 3.0.4-1
rpmlib(FileDigests) <= 4.6.0-1
xorg-x11-xinit
libc.so.6(GLIBC_2.1)
libXmu.so.6
libcrypt.so.1(GLIBC_2.0)
libc.so.6
libc.so.6(GLIBC_2.3.4)

Content of RPM :
/etc/X11/xdm
/etc/X11/xdm/GiveConsole
/etc/X11/xdm/TakeConsole
/etc/X11/xdm/Xaccess
/etc/X11/xdm/Xreset
/etc/X11/xdm/Xresources
/etc/X11/xdm/Xservers
/etc/X11/xdm/Xsession
/etc/X11/xdm/Xsetup_0
/etc/X11/xdm/Xstartup
/etc/X11/xdm/Xwilling
/etc/X11/xdm/xdm-config
/etc/pam.d/xdm
/usr/bin/xdm
/usr/bin/xdmshell
/usr/lib/X11/xdm
/usr/lib/X11/xdm/chooser
/usr/lib/X11/xdm/libXdmGreet.so
/usr/share/X11
/usr/share/X11/app-defaults/Chooser
/usr/share/doc/xorg-x11-xdm-1.1.6
/usr/share/doc/xorg-x11-xdm-1.1.6/AUTHORS
/usr/share/doc/xorg-x11-xdm-1.1.6/COPYING
/usr/share/doc/xorg-x11-xdm-1.1.6/ChangeLog
/usr/share/doc/xorg-x11-xdm-1.1.6/INSTALL
/usr/share/doc/xorg-x11-xdm-1.1.6/NEWS
/usr/share/doc/xorg-x11-xdm-1.1.6/README
/usr/share/man/man1/xdm.1.gz
/usr/share/xdm
/usr/share/xdm/pixmaps
There is 3 files more in these RPM.