As a matter of fact, DILR is all about one's way of interpreting and representing the data in a form which gives more clear and accurate answers in a simple manner. Ideally, there are no modules or materials which can give proper justice to this section. DILR is solely based on the ability of an aspirant to view the data through a different lens. However, coaching institutes and reference materials do provide a good amount of framework which can be helpful for acing this section.
When I took CAT in 2015, I had scored 52.86 %ile only in this section. This year, I scored 99.32%ile in this section with major improvements in test resources, strategies and confidence in attempting the section.
One single biggest thing that aspirants should keep in mind is that never carry on the mindset of a particular section in the following section. This will reduce your speed, confidence and overall score.
Before coming onto resources, I will enlist some basic thumb rules which will ensure that aspirants would avoid such mistakes in the future.
1. Never attempt anything out of blind 'guesswork'. Many will falter here through an unnecessary increase in attempts just because their friends or competitors would have attempted heavily.
2. Don't try stupid things in the exam by trying a differently new set. This will eat more time and you will end up getting frustrated by having wasted your x minutes doing nothing.
3. The most important thing here is the selection of sets. Take a glance of 5-7 minutes and then select only those sets where you find yourself comfortable. After selecting, set the priority of solving sets in terms of time required, Difficulty Level, Bunch of questions it gives etc.
4. Another thing that most will miss out is the half solved sets. If you even know 2/4 questions from a particular set, do it. Just make sure you are there to maximize and perform better by taking every opportunity that CAT places.
5. One of the most pivotal things to keep in mind is READING the data properly. Focus on words very carefully so that you don't have to solve it again out of some silly mistake. Keep checking while solving that you are going in a right direction.
6. Do not loose your nerves if you are not able to make the first set or set in the first go. Do not panic and do not keep your self frustrated. Just think that if it is difficult, it is for everyone out there who is taking the test. Gain yourself and make a comeback.
7. Do not worry if extra details are given. There will be people who will doubt their answers if they are not able to use every single line written. Keeping in mind is one thing and over reading is a different thing.
Talking about the resources, there are many coaching institutes' material for DILR. Be it TIME or IMS or CL or any other. Start with basic kind of sets and basic type of questions. Prepare well on some standard topics like linear arrangements, circular arrangements, direction sense, blood relations, selections with some conditions, puzzles like combos of colours, people,pets, houses etc. in Logical Reasoning. For Data Interpretation, work on basic representations like tables, pie charts, bar graphs, 3D graphs, line graphs, mixed graphs, word problems, Percentage problems and so on.
Take mocks so that you come across variety of data in different combinations. Analyze your mistakes from mocks and sectional tests which will prove fruitful in the final CAT. Learn ratios, percentages, fractions so that calculations become more speedy and you save your time in writing less.
Hope this sheds some lights on preparation.
ALL THE BEST FOLKS!