HOW LONG DOES IT TAKE A PETITION FROM A RESIDENT MOTHER TO A SON?
OR FROM CITIZEN BROTHER TO A BROTHER?
We need more information.
Where is this brother from (country)? (e.g. Mexico, South Africa, etc)
How old is he?
What's his marital status?
I agree with my colleague, but processing times change suddenly from month to month with little notice. A fourth preference sibling petition (brother to brother) can take a decade or more. If you are from the Philippines, then it is unclear whether you should file. The delays are so long that Congress has proposed getting rid of the 4th preference category for siblings.
It usually takes more time for a child who is over 21 years old to be petitioned by a lawful permanent resident parent than a U. S. Citizen. However, if you are or get married, then the petition can be terminated if your mother does not become a U. S. Citizen before the marriage.
I strongly recommend an appointment or teleconference with a competent and experienced immigration attorney, so that you make the right decisions as to how to approach the visa process for family unity purposes. Good luck.
This is general information, not legal advice, and does not create an attorney client relationship.