Hello everyone. I have the similar problem with my company. I am F1 visa holder student and do my OPT in Atlanta and graduated from an university in GA state. I gave documents to my company such as copy of VISA, I 94, and link from IRS.org that says F! Students are not subject of Medical and SS taxes. They send me a mail with says that I need to to have UPP 192 Form. But it is also says that UPP 192 for J1 students, but I am F1.
What should I do? What kind of documents I need to submit to them to proof that I am exempt?

Contact the HR department via phone and discuss it with the person in charge of your account.

The F-1 visa and I-94 should be sufficient to show your exempt status.

I am going to do that, but I need some back ups, like documents or links from the tax law.

Try IRS Pub 519, which can be downloaded from Internal Revenue Service (http://www.irs.gov).