Question

Carlos is biologically male but he does not feel particularly male, nor does he feel particularly female based on this, carlos gender identity is best

Answer 1

Carlos would then be considered by many, Gender Neutral. This is when you do not feel comfortable being the gender you are, however not completely comfortable being the other gender either.
Hope this helps

Answer 2

Carlos is gender neutral. If he does not feel manly of feminine. I hope this answers your question.