No, Data Assist is not compatible with DW CS6, you will need to install Data Assist in an older version of Dreamweaver (You can have multiple DW Versions installed at the same time, I currently have CS3, 4, 5, 5.5 and 6 installed)
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.