Probably a roo - besides the lighter coloring, his legs are also missing that dark wash that most BR hens have.
My 2 barred rocks are supposed to both be pullets (I still believe they are). They are 12 weeks and they are noticeably darker than yours and they both have the dark wash on their legs.
The following link shows what they looked like at about 7-8 weeks of age + their are some other great examples of other m/f barred rock pics here:
https://www.backyardchickens.com/forum/viewtopic.php?id=111466
This is what they mine like now at 12 weeks.
My 2 barred rocks are supposed to both be pullets (I still believe they are). They are 12 weeks and they are noticeably darker than yours and they both have the dark wash on their legs.
The following link shows what they looked like at about 7-8 weeks of age + their are some other great examples of other m/f barred rock pics here:
https://www.backyardchickens.com/forum/viewtopic.php?id=111466
This is what they mine like now at 12 weeks.
