Collider local bounding box

I have objects that require a collider and it can be of any type. In unity the collider's bounds object is an AABB in world space. Is it possible to obtain a AABB local bounding box with zero rotation, that can then be transformed into world space?

If not I have an idea of defining the bounding box using the collider parameters, and then apply the obj transform to put it into world space. But, how can I know which type of collider an object has, from this options: BoxCollider, SphereCollider, CapsuleCollider, MeshCollider?

You can use GetType to find out what type of collider you have attached.

There is another similar thread which you might want to take a look at: