My father is in prison. How can he be my marriage guardian?

Being imprisoned does not in itself remove the right of guardianship; the religious office will decide whether your father can appoint a marriage officiant or must be replaced. In many cases, your father can sign a letter appointing a representative wali before a recognised officer, and the marriage officiant then pronounces the offer (ijab) on his behalf. Start by asking the state Islamic religious affairs office about the documents required. Then contact the prison to arrange a visit or verification. Allow enough time, because the process involves two agencies. If your father cannot be reached or refuses, the marriage officer will explain the next options. See procedure.