It depends on the version of Acrobat you're using. You'll certainly need an installed copy of 3DS Max, as nothing else can read .MAX files.
If you have Acrobat 8.3D or 9 Pro Extended, export from Max to one of the generic interchange formats (.3DS, .OBJ, .IGES, etc.) and import it directly into Acrobat, as they both have translation engines for 3D models.
If you have Acrobat X Pro, you'll either need to purchase the Tetra4D extension (allowing you to directly-import interchange format meshes) or use a combination of tools to convert your MAX file into U3D (poly meshes) or PRC (b-rep curves), which can both be imported natively by Acrobat X without needing any plugins.
There are no free Max plugins for either format and pretty much the only software which can create PRC files is the Tetra4D engine, but you can export the model as an edtiable poly via a translation utility such as Deep Exploration or PolyTrans and save to U3D, or export from Max as a 3DS file, open it in Daz|Studio and save to U3D from there. Although tools like Deep Exploration are very expensive, they can write 3D PDFs directly and will handle almost any 3D file format on the market. If you already have Acrobat X Pro, the Tetra4D extension is a cheaper option but still pricey. Routing a 3DS file through Daz|Studio to make a U3D mesh is time-consuming but completely free.