CAT Preparation

Attempt as many tests as possible. Take test in the duration mentioned for actual CAT.
Good Luck.

Yes, you can start the preparation. Just devote more time for CAT preparation. Application form of CAT for this year is closed. You can start preparation of other MBA entrance exams like TISS, XAT, CMAT or aim for next year CAT exam.

No, gap has no drawbacks. It comes onto play during summer and final placements in college.

If you are good in English and mathematics up to +2 level, then you should start your preparation from just now. If not, then start to work or improve on English and mathematics while pursuing B.Com. CAT is purely based on English, mathematics and both. It tests the analytical and numerical/data analysis ability.
Follow https://shiksha.com/CAT to know more details.

You should opt for TIME coaching institute.

hello,
for quants : Sarvesh Verma
English : Norman and lewis and wren and martin
LR / DI: Arrihant Publication
Or You can purchase complete study material of CL/IMS/TIME from market .

It's absolutely fine if you believe and are confident enough about yourself and your self-study. You can easily get all the study material for CAT. Just be confirmed about the books and authors you would be using are the appropriate and the best once. However, I'll suggest you to join some good coaching classes if you don't think that you'll be able to crack CAT with good percentiles with your self-study. (Because cracking CAT is not enough, you gotta crack it with excellent percentiles to secure admission in a good B-school)

The skill can be acquired through regular practice. Coaching manuals are available in all leading bookstalls. Besides, some weeklies and magazines carry practice questions, mock tests and so on. Coaching assistance will be available with local and national networks such as TIME, Career Launcher etc.