Vivek,
Intralink 3.3 is no longer "supported" by PTC, meaning they won't address bugs or be making any enhancements / changes to the product. It's kind of on the shelf collecting dust. But that doesn't mean you can't download it and install it. The software is still available for download from PTC's site (provided you're on maintenance and have a login) and so long as you install it on the appropriate client OS it should run just fine.
As far as trying to connect to an Intralink 3.3 data server with an Intralink 8+ client, that's not going to work . Intralink 8+ is Windchill based which is an entirely different software package than Intralink 3.x. Plus, being Windchill based there really isn't a client piece - the "client" in Windchill is essentially just a web browser connecting to the web page front end served by the Windchill server.
I think there is a way for a Windchill server to connect to an Intralink 3.x server, but I believe that is meant more for situations where Windchill is managing non-CAD data and Intralink 3.x is managing the CAD data with the two systems talking to exchange information about associations between the separate data types and possibly run change management processes. I think this was intended more as a transitional setup before getting the CAD data into Windchill at some point - I highly doubt this is the path for you, I only mention it because of how you stated "...when installed as a client server".
I'd just install the 3.3 client software that you are currently using to connect to your 3.3 server. How easily it installs and runs depends on the OS since 3.3 is pretty old. I know we have to make tweaks to the 3.4 client install for it to run on Windows 7.
Regards,
Erik
