You can appear for MCI screening Test or FMGE for unlimited attempts. There is no limit set for the same by MCI. However, remember that till you do not clear FMGE, you would not be eligible to take up the internship in India. And without a year of internship in India, you simply cannot get the license to practice or appear for NEET-PG. If you are worried about FMGE, choose MBBS in USA.