Mabey I can help, ive spent 5 years in the CASMR. For the most part an attorny would come in as a 1ST Lieutenant or Captain. Coming in as a Major is possible but unlikely. for my two cents worth I would ask for Captain.
There are a lot of factors to consider (prior service, service in the courts, etc.), but on the whole, I see them coming in as a 1LT. Which, to me, is a fair rank to put them at.
PS. I absolutely HATE that they put that question on the application.
It depends on your legal experience. If you have more than 10 years or more of legal experience, you will generally be appointed at O-3. If you have less than 10 years, then you will generally be appointed at O-2.