I am on H1b visa and I have been paying for tuition fees of my brother who is on F1 visa. I understand that I cannot claim him as a dependant since he is not a citizen. But can I claim the tution fees that I am paying on my returns?

Appreciate any help/comments in this matter.

Thanks

I assume you are asking about claiming tuition fees under either the Hope or Lifetime Learning Credit provisions, correct? Both of these credits are available only to yourself, your spouse, or a dependent for whom you claim an exemption. So the answer is no, you cannot claim these credits based on paying your brother's tuition. See tax publication 970 if you have further questions:
http://www.irs.gov/pub/irs-pdf/p970.pdf