As Chris said, Element 3D will take 3D file imported from other packages. I’ve had it successfully take .obj files exported from 3DS Max, Blender, as well as CAD files imported to 3DS Max and saved out as .obj files. It will take C4D files as well, but I’ve had scattered luck with that (probably depends on the version of C4D the file was saved from).
Zaxwerks makes 3D Invigorator Pro, which does a lot of what Element 3D does, but I don’t know whether it’s as fast at rendering as Element 3D. You can try out either of these, and see which you prefer. Much of it depends on your workflow, and what 3D packages you might own. But back to your question, there is no way to directly import a 3DS file to After Effects CS6.
Joe Bourke
Owner/Creative Director
Bourke Media
http://www.bourkemedia.com