You can get the gen 4 middle evos and the gen 6 final evos by island scanning. The gen 4 starters are on Ula Ula island. Grotle can be found at Ula'ula meadow on Wednesday at level 36 and will know the move heavy slam. Monferno can be found on Friday at route 11 at level 29 and will know the move power-up-punch. Prinplup can be found at lv 35 on Tuesday at route 16 and will know the move power trip.
The gen 6 starters can all be found on Poni island. Chesnaught can be found on exeggutor island at level 45 and will know the move spikes. Delphox can be found on the ancient poni path at level 44 and will know the move wish. Greninja can be found at the poni wilds at level 44 and will know the move bestow.
Hope I helped