Hi, you can easily use svn with RhoStudio!
What you need to know is that RhoStudio (as of v2.2 and earlier) is based on Eclipse so you can install any Eclipse plugin you may need.
You can check this other post where I explained how to install the Marketplace on RhoStudio 2.2.
Once you have installed the marketplace, you can use it to install either Subversive or Subclipse plugins.
Thanks for the confirmation and reply. I was trying to install SubClipse yesterday, but it kept throwing errors during the intstall process, so I thought it was RhoStudio. I tried from home this morning and it installed fine, something must have changed on our firewall at work.