CAT

Hi Akash,
Yes, your past academic scores do not matter for admission into FMS Delhi.
As long as you score a very high in CAT percentile, you can surely get admission into FMS Delhi.

Hi Alipta,
The application window for FMS for the MBA batch of 2018-2020 will open in October 2017.
Feel free to reach out to me for any queries related to admission in DU.

The dates for CAT are still not out. The exam generally happens in late November though.

There is no specific required time for preparation. It depends from person to person and his/her ability to grasp concepts.
For majority students, I'd recommend joining a one year program at a proper coaching center. It typically starts around August, September and coaches you till the exam next year.
Make sure that you give all their mock tests and analyze the results as well (where you went right, where you went wrong). That always help you find your strengths and weaknesses and thus tackle your main exam accordingly.

No. Calculator is not allowed in the CAT exam. However, you get an on-screen calculator that you can use. Having said that, CAT questions are generally framed in a way where you won't really required using a calculator.

yes any graduate can appear for CAT /MAT.

I don't think that you will be able to fill in the CAT form as you do not meet the minimum criteria of 50%. Please have a look at the eligibility criteria for appearing in CAT examination.

You may refer to following link for tips on cracking CAT: https://www.shiksha.com/mba/exams/cat/preparation-tips

No, it will not hamper your admission. Prepare well for the GD-PI-WAT round. Be prepared for justifying the reason for the break in a well-versed manner and all shall be well! All the best!

It is once in a year.