You can't file the I-485 for your brother until his priority date becomes current. You can only file an I-130 for him at this time. If you review the Department of State Visa Bulletin you will see that siblings of US citizens have many, many years of wait times - sometimes around a decade. You may wish to file the I-130 now, but assume that he will want to pursue other immigration options while waiting for a priority date to become available.
Answered on Jun 21st, 2012 at 7:06 PM