My OPT was for my bachelors, i was on my 6th month of my OPT and have my school issue a Masters i20 for me along with the acceptance letter.Then i took an appointment with Ciudad Juarej counsular office and went there for the interview. I didn't have any problem except the lady who took my interview gave me quiet a hard time ...for no known reason.

If you've already completed your masters in one field,then issue another i20 for another field like if  you've done your MIS then issue MBA's i20 and vice versa.

One question they asked me is why you came to mexico and not to your home country to get your visa stamped...i simply told 'em because of time constraint as i'm goin to nepal only for 3 wks max.

let me know if u have any question..