As with all sports, it is important to understand the boundaries on a Basketball court. A player only needs one foot to establish in bounds in basketball.
When in-bounding the ball, 5.
NBA is 12 Minutes and their is stoppages for fouls and out of bounds etc.
Normally, 2 of the player's feet must be 'in bounds' for a completion; however, if a player from the other team is pushing him out of bounds, then only one foot is require to be 'in bounds'.
You have 5 seconds to throw the ball in but you can also run up and down the baseline as long as you stay out of bounds.