Most have a couple of pure breeds which are different each shipment. So one week they may have a certain breed but when they sell out and the next shipment comes in, it will be different. But they usually always have one kind of production chicks like golden comets, red production, black production. They will also carry one type of meat chicken.
Also make sure you know what your looking at. The (most) employees at
TSC don't know anything about chickens, so be prepared for that. Last spring I walked into my local
TSC and asked what breeds they had, beside the Black Australorps that was clearly marked, they told me that they have straight run chicks and pullets. I've read other threads/posts on here where
TSC employees have said that a particular bin was straight run pullets! Usually the pure bred bins will be straight run, and the production chicks will be pullets because they are sex-linked.
Pure breeds that my local
TSC had last spring (in different shipments) was Black Australorps, Barred Rocks, various Orpingtons, Rhode Island Reds, and maybe New Hampshire Red. Don't count on them having any really rare breeds, but like someone else wrote you can order chicks through
TSC. Personally if I was going to have to order a minimum of 25 I would order them myself through a hatchery. That way you can choose to get all girls and you know
TSC is making money off your order. Also you would probably have more of a choice of breeds and combination of those breeds if you order through a hatchery.
I placed an order through Meyer Hatchery in Ohio for March. I was able to order 11 breeds (3 of each breed) and it was for all pullets.