US has separate immigrant and non-immigrant statuses and having one doesn't directly lead to the other (except for certain non-immigrant statuses granted to victims of crime to help the US govt, where three years residence in the US can lead to a greencard). All in all, your petition for permanent residence is separate and independent from your current status in the US.
You need a petition for immigration under one of the pathways, like family, employment, investment, extraordinarily renowned etc. Once the petition is approved, you can apply to adjust your status in the US or can leave the US to apply for an immigrant visa and enter as immigrants.
Only US citizens can petition for their siblings. So your brother can only petition for you when he becomes a US citizen and from the time of petition, it will take around 15-20 years (maybe even more) for you to become permanent residents (this wait time is for sibling petitions).
You can read about various pathways here and see if something suits you: