Number 6 is for sure a pullet. 12 weeks can actually be a challenging stage to tell gender at a glance especially in mixed breeds. Pullets might be starting to get a bit of color, but males may not show male specific feathering yet.
3 and 4 are males if they developed with typical barring. I have had hens with that much white barring, but I knew the crossing was not showing typical barring. #1 and #2 have large wattles for the age so likely males, but breeding could cause this as well. #5 has me leaning male as well. Size and gut feeling, but I would hold off on any decisions until crows, male feathering or eggs confirm.