While there is no 'correct height' per se, we usually recommend around 75mm - 150mm from the top of the bath - ensuring mixer handles are clear of obstruction. With baths there isn't much chance of too much splash back so it is really up to you and your plumber to decide what looks best in your space.
*Please note we always recommend checking the product and product specs with your plumber/builder to ensure the product will work in your space.