The 3DS Import plugin is only for .3ds files, not .max and .lws. The only way I know of to import those files directly (mostly) is using Deep Exploration (https://www.righthemisphere.com/products/dexp/index.htm). If you have access to either of those programs, you can always export to 3ds first and then import to Maya. Or you can use a free plugin to export to FBX (https://www.kaydara.com) and then import that into Maya.