The USMLE step 1 preparation can be done from the 2nd year of MBBS in India. Indian doctors are eligible to appear for USMLE step 1 after 2nd year of MBBS in India. At the end of 2nd year, that is paraclinical PHASE II, you take step 1, then at the end of 3rd year it is step 2 CK and step 2 CS. Step 3 is at the end of your first year of residency. (THIS IS THE ELIGIBILITY) But all recommend to take Step1 after the third year and step 2 after six months into internship as you study a lot during this time.