The most common and most likely answer to this crossword clue is the 6 letter word BOARDS
I've seen this crossword clue in The Guardian
B
O
A
R
D
S
More clues leading to the result BOARDS
- Stage fellows carrying one end of banner …
- Stage di
- Gets on committees
- Stage playwright succeeded, securing Oscar
- Theatre dames with right to drop a couple of places
- Goes on stage
- Pigs taking down pieces of lumber
- Commissions poets describing love
- Stage when steroid finally is injected into swine
- Puts up panels
Buddy explains!

The straight part
We know that "Stage/di/rectors have seats o/rectors have seats o/n them (6)/n them" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case stage/di/rectors have seats o/rectors have seats o/n them (6)/n them = boards.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does BOARDS mean?
BOARDS noun- A relatively long, wide and thin piece of any material, usually wood or similar, often for use in construction or furniture-making.
- A device (e.g., switchboard) containing electrical switches and other controls and designed to control lights, sound, telephone connections, etc.
- A flat surface with markings for playing a board game.
- Short for blackboard, whiteboard, chessboard, surfboard, message board (on the Internet), etc.
- A committee that manages the business of an organization, e.g., a board of directors.
- Regular meals or the amount paid for them in a place of lodging.
- The side of a ship.
- The distance a sailing vessel runs between tacks when working to windward.
- The wall that surrounds an ice hockey rink, often in plural.
- A long, narrow table, like that used in a medieval dining hall.
- Paper made thick and stiff like a board, for book covers, etc.; pasteboard.
- A level or stage having a particular layout.
- A container for holding pre-dealt cards that is used to allow multiple sets of players to play the same cards.
- A rebound.
- (with "the") A stage (as in a theater).
- Structure around a rink for ice hockey.
- A hardcover binding on a book.
- To step or climb onto or otherwise enter a ship, aircraft, train or other conveyance.
- To provide someone with meals and lodging, usually in exchange for money.
- To receive meals and lodging in exchange for money.
- To capture an enemy ship by going alongside and grappling her, then invading her with a boarding party
- To obtain meals, or meals and lodgings, statedly for compensation
- To approach (someone); to make advances to, accost.
- To cover with boards or boarding.
- To hit (someone) with a wooden board.
- To write something on a board, especially a blackboard or whiteboard.
- Examinations given for entry to college or to qualify for a profession.