Rule 6.01(c)
If the catcher interferes with the batter, the batter is awarded first base.
If a runner is attempting to steal home and the catcher interferes while stepping on or in front of home plate without possession of the ball, the batter is awarded first base, and the ball is dead.
If the batter still puts the ball in play despite the interference:
The offensive team has the option to take the play (if better than the interference penalty).
If all runners advance at least one base on the play, the interference is nullified, and the result of the play stands.
The manager can decline the interference call if the play benefits his team.