If I import a model made in google sketchup. Is it possible to provide rigid body constaint to that model. If yes then please explain how?

You can add a rigidbody to the object and it will provide physics to that object. I don’t think that’s the problem you’re trying to solve. Do you mean a collider rather than a rigidbody? If so you can to use a mesh collider but you need the mesh for the object and it may still have collision / performance issues.