You could try one of these (i386 versions are also available):

http://opensource.wandisco.com/centos/5/RPMS/x86_64/

They're made fore CentOS, but AIUI, should work on RHEL as well. 1.6.17 isn't there, but newer versions are; I'd suggest trying the latest, 1.6.23-2.

Are these "Apache standard SVN" editions? Or have they been enhanced by WANDisco?

--
Felipe