CAT Preparation

CAT is an exam where your basics need to be strong. They will ask you questions anyhow by combining two topics together or putting up a single topic example in a unique and different way.
The main topics that a student should prepare would be time distance, time speed, probability, ages, dice, ratio and proportions, etc., from Quants.
Verbal is considered to be the most difficult area in CAT exam as you need to have a strong hold on English language i.e you must be having a very good vocabulary, grammar should be perfect, etc.
For Reasoning, your focus should be on matrix puzzles, coding-decoding, sequential output, etc.
You need to be very strong in verbal and reasoning to crack CAT as these are the two main sections where you can score more than others if you practice well.
So, start with basics as those are the most important ones.

As per my experience I don't think that an year gap affects for CAT preparation adversely affects your chances of getting admission in any institute in IIMs or any other institute of India. The entire interview process is meant to gauge the students on their knowledge, skills and attitudes as well as their inclination of doing a MBA program.
If you are dropping out of your current job for one year there should be a justification as to what were the reason for opting out of your job. There are various examples of students who have scored a hundred percentile while working and thus the interviewers always discuss the reasons for dropping out. But, if you are able to justify it well and convince them about yourself. I personally don't think that it would negatively affect your chances into IIMs or any other institute of India.

Hello,
Most of your task is done for IIFT if you are preparing for CAT. Difficulty level for both the exams is at par. The only difference is the General Knowledge section which can be easily covered by Reading newspapers on a daily basis.
Ensure to solve mock papers for IIFT to get a look and feel of how the pattern is, what the difficulty level of the exam is.
Focus on your CAT preparation and IIFT preparation will follow.
Remember, do not try to put your leg into both the paper as far as preparation is concerned. Just focus on your CAT preparation. Try to complete your syllabus well before time so that you have time to agile yourself to set for IIFT also. Hard work and smart work will definitely make your way for both of the entrance exams.