Hi Anis, unfortunately one thing that can complicate things is that the default OBJ importer that Max has is not really very good.

I have heard from some people that this other max OBJ import plug-in from here:
http://www.guruware.at/main/objio/index.html
can work better, so that may be worth a try.

Also make sure to set your export from MoI to be "Quads & Triangles".

- Michael