"No, it doesn't" in common
Slightly deeply
Higher versions of SVN-clients are backward-compatible with all relesed versions. Older versions just can't handle later improvements
Long, nervous and almost obscenely
1.6 is old, outdated and not maintained version of SVN. Only dumb, lazy and indifferent marmoset (not Admin per se) leave it on server for mission-critical tasks now: while most of more recent enhancements are client-side, decent client-server pair (1.8+) offer a lot of usefulness under the hood (read 1.8 changelog and 1.9 changelog at least in "New Feature Compatibility Table" parts)