Chances are, he came into the US illegally? If so, he will need to have an approved unlawful presence waiver. If granted, he will be able to consular process back into the US after you file his documents and the documents are approved. You should file while he is here though and you should get the unlawful presence waiver approved while he is here. Only after that can he travel back to Mexico.
Answered on Aug 05th, 2014 at 10:46 PM