The process of sponsoring a sibling takes approximately 14-16 years from the time of filing. This is so because the Congress has set limitations on the number of immigrant visas issued for siblings of US citizens. As such, there is a que of approximately 14+ years for the visa numbers to become available. There is no expedite process available in that que. The date when your brother will be eligible is strictly controlled by the date you filed the petition; that date is known as "priority date".