You can attend ODS after completion of your bar examination. However, before you can attend the Basic Lawyer Course at NJS, you must have completed ODS and attained successful bar examination results. (Ref: Guide to the Navy JAG Corps)
This is correct, speaking from experience. You may attend ODS while waiting on bar results. You cannot attend NJS until you know if you've passed or not.
Also, I'm at NJS right now; everything is going well! ODS sucked, mostly because being treated like a shlub when you're a lawyer is something that is difficult to come to terms with. However, NJS is pretty fun though! It is nice to finally get to know more about what our jobs are going to be, I'm finally starting to feel like a lawyer. It is also nice to have some money coming in, albeit the incorrect amount. It takes awhile to get your pay sorted, especially if you're prior service! Let us know if you have any questions!