Some percussion instruments like Tabla, Bongo drums etc need them to be tuned to specific pitches. If not tuned correct, they would sound weird. So for such instruments, usually custom drum kits are created with the notes tuned to specific pitches. When a style/song has such a kit and if the style needs to be played in a different scale than the one the drum kit is tuned to, the style/song needs the drum kit which is tuned to the correct pitch to be assigned to it. This needs to be done from the style edit/sequencer page if there are multiple assigned to the same track. But there is an easy method for this in Korg Arrangers.
It is using the drum edit feature in the track controls page from the main menu. In drum edit page, different drum families within the same track can be assigned with different settings like volume, tuning, eq etc. So for quick tuning the percussion instruments, the tuning options in the drum families can be used.
Watch this video for the detailed steps to do this.