Did your brother petition for you more than 12 years ago?
If not ... then this is an academic question ... you need to wait 12 years, at least.
PROFESSOR OF IMMIGRATION LAW for over 10 years -- firstname.lastname@example.org -- www.capriotti.com -- This blog posting is offered for informational purposes only. It does not constitute an attorney-client relationship. Also, keep in mind that this is an INTERNET BLOG. You should not rely on anything you read here to make decisions which impact on your life. Meet with an attorney, via Skype, or in person, to obtain competent personal and professional guidance.
As Attorney Capriotti indicated, there is a long wait for sibling sponsorships. If you are in the US legally at the time your case becomes current, yes, you can adjust your status without leaving.
Niren & Associates
(toll free) 1-866-929-0991
Offices in Toronto and Buffalo
Legal disclaimer: For specific advice on your case, Mr. Minawi can be reached at 1-866-929-0991 ext. 206 or by email@example.com.This answer does not establish an attorney client relationship. www.visaplace.com
A wait of 12-14 years is what happens on a sibling's petition.
Behar Intl. Counsel 619.234.5962 Kindly be advised that the answer above is only general in nature cannot be construed as legal advice, given that not enough facts are known. It is your responsibility to retain a lawyer to analyze the facts specific to your particular situation in order to give you specific advice. Specific answers will require cognizance of all pertinent facts about your case. Any answers offered on Avvo are of a general nature only, and are not meant to create an attorney-client relationship.