3ds Max provides a number of different ways to create and use normal bump mapping, but the most straightforward and simplest workflow involves these steps:
The low-resolution model should have the general shape and outlines of the high-resolution model, and typically it should be a bit smaller, so that projected detail in the high-res model will appear to be above its surface.
The Render To Texture dialog appears.
3ds Max opens a selection dialog.
3ds Max applies a Projection modifier to the low-res object.
3ds Max renders the Normals map, which stores normals data from the high-res object. As for other kinds of texture baking, it creates a Shell material and applies that to the low-res object, with the Normals map assigned as the bump component.