I think they are both pullets...if 5 to 6 months old.
If that is their age, then one pullet is underdeveloped for that age...I would expect her to look more like the other one...who looks almost ready to lay.
On the more developed bird, if that were 3 months old, I'd say roo, however I don't see hackles or saddles nor sickle tail feathers, nor the large wattles that I would expect of a young but mature 6 month old rooster.
Hens do get combs and wattles, just no where near the size of the guys. And I've had my Rhodie pullets get black tails and flecks of black throughout, even worrisome splotches....do to being production RIR's.
I'm basing my guess on the lack of comb size and lack of male feathers if truly 5 to 6 months of age.
Lady of McCamley