Although ewe have not found any specific information about any type of a3d to 3ds conversion, it is certainly related to potential export between 3ds max and Amapi 3D formats.
In this case you will probably have to rely on some dedicated 3D conversion utilities like 3D Object Converter, or similar to successfully convert your 3d model from A3D to 3DS format.
Updated: September 5, 2023