Question: I am using Tortoise SVN. I made a mistake and committed the files(Revision 6). I want to revert back to revision 5 and commit the files again. How can I do it???

Answer: 
Go to "SVN Show log", right click on the offending revision and select "Revert changes from this revision". Your working copy will look as before. You can then commit to definitively undo the changes, or make valid changes before.
Hi If it is on your local desktop you should be able to right click - tortoiseSVN - revert. This should show past versions. Try

<http://tortoisesvn.net/docs/release/TortoiseSVN_en/tsvn-howto-rollback.html>