Hi Jawan1, this article from Shusterman\'s updates will clear your doubts.
Good luck.
* Due Process Rights - Let\'s suppose that the worst case scenario
occurs: INS investigates your already-approved visa petition and
decides it might have been granted in error. In this case, the INS
must first serve your petitioner with a Notice of Intent to Revoke
(NOIR) your petition. The petitioner may attempt to rebut the
information contained in the NOIR. Even if the INS ultimately
decides to revoke the petition, its decision may be appealed to the
INS\'s Administrative Appeals Office (AAO) in Washington, D.C. If
the AAO affirms the decision to revoke the petition, this decision
may be challenged in Federal Court. Only when the revocation
becomes final may the INS rule on your application for adjustment
of status. In the meantime, you are entitled to renew your
Employment Authorization Document (EAD) and your Advance Parole
travel document on an annual basis.
* Waivers of Inadmissibility - What if you are not admissible for
permanent residence because you have been convicted of a crime or
have committed immigration fraud? You may be entitled to seek a
waiver on the ground of inadmissibility. If INS denies your waiver
request, you may appeal the denial to the AAO.
* Right to Renew Adjustment Application in Immigration Court - What
if your adjustment application is denied? In most cases, you can
renew your application before an Immigration Judge in a removal
proceeding. However, if your visa petition has been revoked, the
Judge has no jurisdiction to overrule the INS\'s decision to revoke
the petition. Even if you are not able to renew your adjustment
application before the Judge, you may be eligible for alternate
forms of relief from removal including cancellation of removal,
asylum, etc.
* 180-Day Portability Rule - If, in the case of an employment-based
petition, the INS fails to decide your application for adjustment
of status within 180 days, you have the right to change to another
job as long as the new job is in the same or a similar occupation.