It is a form used by applicants who entered the country illegally and have immediate family members who are American citizens or who have green cards, such as parents or a spouse. Using this form, you can apply for a waiver of inadmissibility to avoid an entry ban of three to ten years.
A waiver application, Form I-601A, must be submitted to the U.S. Citizenship and Immigration Services (USCIS) before you return to your country of origin. If the USCIS has approved your application, you can attend a green card appointment in your country of origin at a U.S. embassy or consulate. This form must be submitted to USCIS along with the required supporting documentation.