If a right arm off spinner is bowling around the wicket to a right-hand batter and the batter attempts a reverse sweep does the shot negate the need for the ball to be pitching in line with the stumps for the batter to be given out lbw.

In other words can the batter be given our lbw if the ball pitches outside leg stump just because the batter looks to play a reverse sweep.

The Laws of Cricket (and LBW) apply regardless of what shot the batter plays.

For the sake of the reverse sweep or switch hit, the batters leg stump is determined by their stance when the bowler starts their run up. So, if the batter is a right hander as the bowlers starts to run, they remain a right hander (and leg stump is the same) regardless of the shot they play.

Therefore the ball cannot pitch outside their leg stump for the bowler to be given a LBW decision (also regardless of their shot).

I hope this helps.