If you got RT (Reappear in Theory) in Accountancy, which was your additional subject in Class 12, and you applied for improvement but got RT again, here's what you can do:

1. You can appear for the Compartment Exam  in Accountancy, which will be held a few months after the main board exams. This will give you another chance to clear the subject and improve your overall result

2. For the Compartment Exam  you will need to pay an additional fee and fill out the compartment form.

3. If you clear the Compartment Exam your result will be updated, and you will be eligible for admission to undergraduate courses like B.Com, BBA, etc.

4. If you fail to clear Accountancy even in the Compartment Exam, you can still apply for admission to CE (Correspondence Education) courses offered by CBSE in the future

5. CE courses allow you to reappear in the failed subject(s) along with the main board exams in subsequent years until you clear them

So in summary, your best option is to focus on clearing Accountancy in the upcoming Compartment Exam. If you still don't clear it, you can always apply for CE courses to reappear in the subject and improve your chances of getting admission to your desired undergraduate program.