My scores are not improving in DILR while doing the sectional test but when I am solving the same problem after completing the mock I can able to do the particular set. What should I do in this 14 days could anyone help?

Write the test with the assumption that you want to do just 2 easy peasy sets. Just 2. Not a question more. When reading the set, if you find it difficult to understand, move on to the next one, because you want just 2 sets. Now then put the time to think coolly while solving. I hope this helps. This works for me.

I forgot to select IIMA FABM as one of my preferred courses. And I am quite inclined towards it. Can I possibly do anything now?

Admission into IIMA FABM is based on CAT score and you need to apply during the CAT application process. The window for editing the application is closed and you will not be able to apply to that program now.