Golf Course Superintendents Association of America recommends rakes are placed outside

Both the above have their positives and negatives.
There is no rule and ‘it is a matter for the Committee to decide where it wishes rakes to be placed.’
The Golf Course Superintendents Association of America recommends that rakes are placed outside bunkers, laying with the tines upwards and placed in the direction of play.
So remember, tines up, rakes parallel with the direction of the course outside the bunker, unless your committee or course has its own rulings on the matter.