Hi my wife had 7 year old son from other marriage .

You are not clear. Are your wife and stepson in the US? If not she should supply a new medical exam. If the interview was in the US, the exam is...

Are you seeking employment in your field? Nursing is not on the stem list but some nursing positions are eligible for H1B visas.

Can my US citizen brother request me ?

You really must consult with an immigration lawyer. There are several things needed to discuss.

Green Card

I agree with my colleagues advising you to consult with an immigration attorney. Her expired visa should not be a problem.

Can I petition my married son once I become a citizen? .

I assume he is now currently in the US. It will take 20 years for him to come to the US. Speak to an immigration attorney to explore options.

Canadian citizen US visit

Your mother can come here for six months or you could visit her. After frequent visits she will be questioned at the border.

I am an undocumented immigrant from India living in shadows from 2009, I am planning to turn my self in to ICE

India is up to 2005 so your father's case cannot help you. On what grounds do you want a lawyer to fight your case? If you are ready to pay back...

Can I apply to become U.S Citizen even when my wife petition is under investigation by the USCIS?

Only you know the reason for the investigation so no one on this forum can advise you. Please seek advice in private from an immigration attorney.

What documents must take my son to the green card interview?

He brings proof of his relationship to you and proof of your relationship to his step mother. That would be original birth certificates and...

I have a friend that decided to marry his fiance in United States. She has tourism visa and he is an american citizen.

Your friend should consult an immigration attorney. The consultation will lead them to the right direction.