You have at least one Easter Egger (Ameraucana mix)...the chipmunk with puff cheeks and pea comb with I think (hard to see in photos) green legs.
Probably another Easter Egger... it appears to have a little puff to cheeks and green legs as well...otherwise it could be a number of things.
You probably have 2 Barred Rocks....black with white head dot and yellow legs.
You may have 1 Black Sexlink...which will be a pullet....all black chick. Which having bought at auction gives me suspicion to the 2 black with head dot as possibly being Black Sexlink males....the BSL girls are all black (with red bleed through as adults) and the males are barred. Really hard to tell at this age between the two (BR vs. BSL male) if you don't know the history.
The last red brown chipmunk chick may be a Welsummer as it has yellow legs and no puff to cheeks. It could also be a Brown Leghorn. It is hard to tell a Welsummer chick from a Brown Leghorn chick if you don't know the history. As adults, they look similar as well both being brown partridge patterning (Brown Leghorn as compared to a female Welsummer). The Welsummer will be redder than the golden brown of the Leghorn. Welsummer will have red earlobes and Leghorn will have white earlobes. Welsummers are different colored as to females and males. The females develop a salmon chest with the reddish partridge on the back with gold hackles, while Welsummer males develop a black chest and gold color block. So watch development.
The white chick is not a White Leghorn as there is a lot of black patterning coming into those wings. Too early to tell as it could be a number of things. It might be a Delaware or could be a Light Sussex. Time will tell.
Since these are auction purchased, they could have come from almost anywhere and could be barnyard mixes as well...but they look typical of a hatchery purchase with someone selling spare chicks from a minimum quantity order...so I am assuming standard breeds.
LofMc