@pk , Thanks for the reply.
I have few more questions based on your reply.
a) if I go with option a) why should i pay 15.3%, shouldn't i be paying only my share? Should i using form 8919 to amend?
b) No, W2 had blanks for boxes 3,4,5,6. Hence no warning.
c) Not sure about being immune to FICA Please this DHS, https://studyinthestates.dhs.gov/stem-opt-hub/stem-opt-frequently-asked-questions
"It depends. Under current tax laws, if your STEM OPT participant is exempt from payroll taxes, you save an amount equal to 6.2 percent of the STEM OPT participant’s salary up to the taxable wage base and an additional 1.45 percent of the total salary that would have been your contribution to the Social Security and Medicare trust funds. STEM OPT participants generally are not subject to FICA taxes or Social Security and Medicare contributions until after the first five calendar years that they hold an F-1 nonimmigrant status, but many STEM OPT participants will already have accrued such physical presence and thus will be subject to FICA taxes."
d) I was not employed by an university after graduation and also I am not attending classes.
I am really confused about this.
