Sorry for so many photos! i would like to know (if possible at this age)what gender they are, and if the white chick is a brahma breed(or cross bred brahma).
They appear to be around four weeks, a bit early to guess gender. I see a few that could be cockerels, but there are too many photos and not enough that are closeup enough to make a very good guess.
The thing to look for are comparisons. Very pale insignificant combs will likely be pullets. The ones with reddish casts to the combs that are noticeably bigger and that also have wattles developing are usually cockerels.
By six weeks, boys have conspicuously red combs while the girls are pale.
For ultimate confirmation on a cockerel, at around ten weeks, you will see curved sickle feather beginning to shoot out from the tail.