I'd say you Leghorns are very unlikely to go broody, although someone on another forum just posted about their own broody Leghorn, so you never know. The RIR is also probably not going to go broody -- they have had it bred out of them. I think, if memory serves me well, the NH is the most likely to go broody of all your hens. Just not sure what the probabilities are.
If you really want to have a broody hen you should try Silkies -- they can be broody to a fault. Also, a lot of folks love their broody Cochins and a little less so their Orpingtons. There are others, but I've never raised them so not sure.
If you really want to have a broody hen you should try Silkies -- they can be broody to a fault. Also, a lot of folks love their broody Cochins and a little less so their Orpingtons. There are others, but I've never raised them so not sure.