Rule: 6-2-d
If the catcher interferes with the batter, the batter is awarded first base, and all runners advance if forced.
The offensive team can elect to take the result of the play instead.
If a runner is stealing home, and the catcher interferes while stepping on or in front of home plate without possession of the ball, the ball is dead, and the batter is awarded first base.
If the interference occurs on a swinging strike three, the batter is out, but the catcher’s interference is ignored.