To get it to go to the R6 menu instead of the DS menu, switch on the DS without any cards in it, click the small DS icon at the bottom of the screen (lower), click the spanner/wrench, click the top icon (arrow pointing into a rectangle), then select Auto mode.
As for Sakura, i think there is a hacked DLDI version, that should work on the R6, but it probably does not load any games or homebrew.