The light from the objects with the highest redshift that we currently see (z=6) was emitted about 15 billion years ago (roughly the age of the universe). At the time that the light we see was emitted, the universe was much smaller, so the separation between us and the object was less than 15 billion light years. As the universe expanded, however, the separation between us and the object grew. Thus, as the light traveled, it had to compensate for this extra distance created by expansion. It didn't actually reach us until the present time, 15 billion years later.

The PRESENT state of the objects we see at z=6 is unknown, though we can estimate their PRESENT distance from the expansion rate of the universe. I assume this is the number you quoted, 27 billion light years. We can't see them in their present state, so we don't know for sure how far away they are. They are outside of our "light cone", so to speak.

Hope this helps.