Can we bring our minor son while our green card is still being processed?

Hello! My older son is getting his citizenship and he's going to apply for us, his parents. My husband and I have a 19 year old boy still living with us, so when we go to the U.S.A., we will have to leave our son here. We're Mexicans and have B2 visas. Is there a way or permit other than the 6 month permit, to take him with us to stay legally in the U.S.A. while all the process is happening? Maybe he can go to school there because we don't want to leave him alone in our home country. Thank you in advance.