My friend got married to an illigal; person for 6 years now he has his papers thanks to her but she found out thaht tha is all he wanted from her can she do something about that? Is this illegal?

Illegal yes, but since they stayed married for 6 years ( over 1/2 marriages don't last that long for people in "love"
It would be hard to prove it in court, so just divorce them, and move on

If he lied during his interview with Immigration, that is illegal. She can contact them & let them know what has happened. Then, it is in their hands whether to deport him or not.