After having a quick read through crymod and some other googling I am fairly certain that the latest version of Max that has an official Cryengine2 exporter is 3DMax2009(v11).
There could be user-made exporters for later versions of Max, but I couldnt find any myself, and to be honest with you, I would probably shy away from user made exporters, but thats just a personal preference and comes from bad experiences with usermade export plugins on various modelling packages in the past.
I have read on crymod, that there will be exporters for max2010 when the CryEngine3 ModSDK is released(no word on backwards compatibility with ce2 though).
I have also read of people having some success using the "BlueMars" version of the max2010 exporters with CryEngine2, but just as many seem to have had issues with it.. here is a link discussing it..
http://www.crymod.com/thread.php?postid=700756 .. relevant discussion is around 4-5 posts from the top. It does look a little "hacky" to me though, so is probably not a good idea.. I'd stick with 2009 until an official exporter is made available for 2010+... just my opinion.
All of the official exporters and plugins are provided as part of the ModSDK downloads that you can get from Crymod.
