While you were already placed in Removal proceeding, you can still apply for Lawful Permanent Residence if you are married to a US citizen spouse. Caveat, however, once you are in removal proceeding and get married to a US citizen, you must prove that your marriage is done in good faith, not just to avert immigration proceeding against you.
Filing of Immigration Petition (I-130)
Even while your removal hearing is pending at an immigration court, your US citizen spouse can file an immigration petition on behalf of you with USCIS. Unlike an ordinary immigration petition, however, this type of petition will require both of petitioner and beneficiary to be present for an interview at USCIS field office for adjudication.
Motion for Administrative Closure or Prosecutorial Discretion
Depending on situation, your attorney can file motion to administratively close the case for you in your removal proceeding. If the motion is granted, your case is administratively closed and gotten rid of judge’s active docket. In most cases like this, you can have more time to stay in the United States.
Motion to Re-calendar or Termination
If your removal proceeding is administratively closed, you need to reopen the case at immigration court by jointly filing motion with the district attorney to re-calendar the case back on the active docket. Once the case is re-open, your attorney will ask the immigration judge to terminate the case so that you can continue to file an application for Adjustment of Status with USCIS.
Filing of Adjustment of Status with USCIS (I-485)
Once your case is terminated, you can file Adjustment of Status with USCIS just as you would do in other ordinary cases.