I worked with a student that was in a very similar situation. He was able to take the board exam, but it took much longer for him to get approved for examination. Boards typically want all the official court documents, rehab statements if applicable, personal statements, etc. They take their sweet time reviewing and processing all that, but as long as it's just an isolated DUI and no evidence of repeat offense or habitual abuser, etc. it should go through. Expect at least an extra month delay.