How to create a soft type for CAD Document?

Ranjit,

Which version of Windchill are you using? If you're using 9.1 or earlier then it's not possible to soft type a CAD Document.

Starting in 10.0, you can create the soft type within Type and Attribute Management:

If the soft type isn't appearing in the New CAD Document wizard as an available type then one of the following is probably the issue:

1. The type is not marked as instantiable in Type and Attribute Management (less likely)

or

2. You have not created any CAD Document templates that are of that particular soft type. See my answer in this thread for more information.