The Hungarian Citizenship Exam consists of two parts: written and oral. It isn't a language exam, but a test and an interview on your knowledge of Hungarian history, literature, culture, geography and civil law. As for the language, you could take the ORIGO Egynyelvű vizsga (Hungarian-only exam) by Idegennyelvi Továbbkepző Központ; it is recognized by Hungary as a test of proficiency.