To me it looks like a rooster but here's a good way to tell.
this way to tell if it is a boy or a girl is not perfect, but it is a highly educated guess.
here is what you do, you can hold the chicken on its back.
If it starts kicking, then it is most likely a boy because boys tend to like to fight back.
If it kicks just a little or not at all it is most likely to be a girl.
You can also tell whether it is a boy or girl with a different method.
You can hold it by the back of the neck like a cat would do to its chicken.
And the results of the first one apply.
Hope this helps!