Hmm, from the Brahma pics, looks like a pullet. The RIR could go either way because pullets of that breed do have combs by then. I'm leaning toward cockerel. Here is a picture of my RIR cockerel and his sister. They are 7 weeks old in the picture in this thread. Look at post #5. You can't wing sex after the first couple of days of life.
Well, I dont know that you can wing sex RIRs at all; should have made that clear. I just wanted to say that it has to be done as newly hatched chicks, can't be done later.
None of those methods are accurate, only on some breeds is wing sexing possible.