You may file Form I-191 if you are a lawful permanent resident and you believe you are eligible for relief under former INA section 212(c).
Congress repealed former INA section 212(c) effective April 1, 1997. However, the U.S. Supreme Court decided in 2001 that the repeal does not apply to lawful permanent residents who pleaded guilty to a crime before April 1, 1997 (INS v. St. Cyr, 533 U.S. 289). In Matter of Abdelghany, 26 I&N Dec. 254 (BIA 2014), the Board of Immigration Appeals held that relief under former INA section 212(c) is also available to otherwise eligible lawful permanent residents even if they were convicted following a trial before April 1, 1997.
Note: The form was previously titled, “Application for Advance Permission to Return to Unrelinquished Domicile”.