Question: What kind of violation is it if the feet hit the floor before the ball is released?
About the article "Basketball", section "Shooting".

Candidate passages:
The FIBA rule is similar to the NCAA rule but it has two minor differences.
First, there is no paragraph 4.a of Section 72.
Therefore, it is a violation if the player, after coming to a stop and establishing the pivot foot, lifts it before the other foot without a dribble.
Second, when player falling, lying or sitting on the floor:  It is legal when a player falls and slides on the floor while holding the ball or, while lying or sitting on the floor, gains control of the ball.
It is a violation if the player then rolls or attempts to stand up while holding the ball.  
  To achieve a level, each of the five players must hit the ball at least once.
No one player may hit the ball more than once in a row.
Both feet must remain firmly planted on the ground.
If a foot is lifted from the ground (or slid along the ground), that attempt is void, and counting must begin again from 1.
If you see something, say something: If a player sees a violation, they must report it to the others by shouting "I saw something!"
Players can report their own violations in the same way.
Players must count aloud the hits in each attempt.
Players are responsible for counting their own hits and no one else's.
If a player forgets, that hit is not counted, and the next hit will be counted according to the preceding number.
A player has until the following hit to count their own hit.
When a tenth hit is achieved, the hitter, instead of calling "10!"
must instead yell "Cherryball!"
Shouting the number instead of "Cherryball" will result in the invalidation of that attempt.
The player who picks up the ball after a failed attempt, or after the final hit of a successful attempt serves it to start the next level.
The serve counts as hit 1 for that level.  
Players have the choice of either hitting the ball off of the table or “Bodying” it to either side for a better shot off of the ground.
Because a player’s hands and arms are considered extensions of the paddle, you cannot Body the ball with either your hands or arms.
If you do, this is considered a shot.
You also cannot body the ball with your foot or your leg below the knee.
This is a “Foot” and the player that does this should pick up the ball and serve.
Additionally, you cannot Body a ball that has already hit the floor, even if done by accident.
If the ball gets stuck in an article of clothing, that player may take one step before inducing the ball to drop on the floor, at which time normal play resumes.
This is the same rule if the ball rolls into an empty cup. 
After a fair serve the receiver strikes the ball so that it either directly or indirectly hits the front wall before hitting the floor a second time, goes out of bounds, or strikes the tin.
Players thus alternate hitting the ball until one fails to make a fair return.
The ball can only be played off the back wall if the ball first hits the back wall.
A ball may hit anywhere on the back wall if it first bounces off the floor—otherwise it must stay below the back wall out line.
Unintentional interference results in a "let"—the point is replayed. 
If the immediate next delivery following a foot-fault no ball is "any kind" of no ball or a wide ball, then the free hit carries over to the next ball also.
Even if the free hit ball is judged as a wide ball, the striker can only be out 'under the circumstances that can apply for a no ball'.