Is it possible to have keratoconus and amblyopia all in one eye ??

Of course: Amblyopia comes from issues in one eye compared to the other in infancy and childhood and is a permanent change in the vision. Such an eye is not immune from getting keratoconus at a later age. So both can coexist but do not cause each other.

Yes: These are separate conditions, which could occur in the same eye.

Keratoconus: A lazy eye can occur in keratoconus. It important that you see a specialist who can help you determine whether vision is not good due to keratoconus alone, or due to amblyopia (lazy eye) plus keratoconus.