Uh, what exactly is the problem? Do you think that's too big or too small?
I think it's actually about average, maybe a little above average and it might get bigger, i'm not an expert. But don't worry about it, there's nothing you can do about penis size, and 6 1/2 is plenty.
That's about what I am, and i've never had any complaints - in fact complaintwise, the only times i've gotten them were because the woman had a short vagina and I knocked her ovaries - kinda like getting kicked in the balls for a man apparently.
Anyway, any longer and you won't even be able to get it in all the way with a lot of women, which means you won't be able to grind your pubic bone against her clitoris, which is pretty effective for getting women to orgasm before you do.