Nicastro Piscopo, APLC | Louis M. Piscopo
If you are a U.S. Citizen you can petition them if they are single or married. If you are a Green Card holder, they have to be single. However, their priority dates will not be current for 5-12 years if they are over 21 years old. Moreover, unless they are protected under Section 245(i) they are not eligible to file for adjustment of status to obtain their Green Card since they are of status. If you are a US Citizen and they are under 21 years old and last entered the US legally, then they can apply for their Green Card in the U.S. and it would only take a few months.
Answer Applies to: California