1.Can we create Terrain model in our 2D view model ?
2. How to create 3D view of our 2D master model?
Set active a terrain and you will create an associated 3D model to your 2D model.
Set active a profile and you will do the same.
Terrain will be created in 3D.
You can create terrain based on 2D element with active profiles, the terrain will be created in 3D.
One easy way to get what @JeremieDL said is to create a H line and assign constant elevation from vertical geometry command. You will automatically get the 3D model.
A terrain model (or any Survey) for the existing should be created in a DGN created from a 3D seed file that has only a 3D model.Then, this DGN will be referenced in the DGN of the design.