Obstructed Balconies is a design issue that comes from the Quantum / Anthem predecessors - Celebrity Solstice class ships.
Cruise lines are often reluctant to admit that some balconies on their ships are in fact obstructed.
RCI did a better (not 100% perfect) job: on the Quantum they marked "obstructed view balconies" as a separate category.
Please see my detailed diagrams (link).
Balconies on Deck 6 in recessed in areas are obstructed.
RCI makes a few exceptions on deck plans.
However, I would thoroughly avoid all recessed in areas on Deck 6.
Some of Deck 6 balconies are badly obstructed. Some are not as badly...
But...still very disappointing.
To be on the safe side: avoid recessed in areas unless you get a significant discount.
Davits are the worst obstructions.
Also avoid 6130 and 6530 next to the bump-out on the forward hump.
There are no "officially" obstructed balconies on this deck, but in fact most of them are at least "partially" obstructed (see the diagram below).
As a precaution, do not book cabins in the pink area.
There are a few that I would never pay for: those in the aft end of Deck 7 are located next to a huge bump-out (the Two70 Lounge).
I would also be careful with a couple of forward balconies on Deck 11 due to the presence of the Bridge.
Note the Bridge.
I would skip at least three or four forward balconies due to the presence of the Bridge and privacy issues.
Click to enlarge