Can a Catholic and a Jacobite get married?

Answer 1

Yes. If you are referring to the sacrament of marriage in the Catholic church AKA a Catholic wedding then I believe both people have to be baptized Christian. One of them must be Catholic obviously. Here's a link.

Answer 2

Most religions that are called "Jacobite" are variations of Orthodoxy, thus not Catholic. To marry an Orthodox, one would need special permission from your bishop, through your local priest. The priest would be able to tell you what was involved, and what you had to do to obtain such permission. My advice would be to have a sit down chat with your Jacobite and find out exactly where religion stands in his or her life. He or she may be perfectly willing to convert, in any case, they would have to agree to raise any children as Catholic.