Sixth Sense (and Superior Reflexes) are both available in Age of Rebellion to Quartermasters and Ambassadors as well. There, they are both non-ranked talents.
This has been confirmed to be an error on the Developer Answered Questions thread.
Force and Destiny lists the talent Sixth Sense as Ranked. Edge of the Empire lists it as Unranked. Which is correct?
It is unranked; the listing of it in Force and Destiny is in error and will be corrected in reprints.
Hope this helps!
Fantasy Flight Games
The final say is on the errata of each book.
That is because the three (with a fourth coming soon) settings are cross compatible. That means that one game takes the previous one into consideration, and not only that, but also the next book. As Edge of the Empire was being written, they already had plans for the other two books. Which means that certain rules were written with that in mind (like the Force Sensitive Exile).
So, you can expect that any republishing of a rule, should be compatible with the same rule from the previous book. If not, expect an errata for that book coming up.
This information can be found on the product page of each book, but was already there when Edge of Empire came out (Source):
Expanding Your Star Wars Universe
Edge of the Empire is the first of three standalone, but fully cross-compatible roleplaying systems. Each introduces a unique dimension of the Star Wars play experience, but the core mechanics are fully interchangeable. Players and GMs will have the option to use these materials separately or combine them as they see fit in order to carve out a unique, custom roleplaying experience.