Can an illegal alien adjust status if s/he has a job offer from a US employer?
Can an illegal alien adjust status if s/he has a job offer from a US employer?
Did the alien enter the country legally?
Did the alien overstay a prior visa?
If you're not eligible to work in the U.S., the employer shouldn't be hiring you in the first place.
As a person who legally hires foreign nationals in a variety of situations, I can tell you the chances of him getting on to some work-permitted status while illegally present is nil. He will need to leave first while the hiring company flogs the paperwork required to make the change. It can take a year. I actually parked one of my Indian guys in contract status up in Canada while we worked through it.
Depending upon the length of the overstay, the employee may have triggered a period of ineligibility to even enter the United States. The employee can't get back into status through employment without leaving.