Mohit, 98-99 percentile means you can afford to have hardly 2-3 wrong answers.  98-99 percentile precisely means you should score better than 99 percentage of the people who have appeared for ATMA. Which means, there can be no room for errors. ATMA is conducted both offline and online for a duration of 3 hours. There are 6 sections in the exam paper:

Analytical Reasoning Skills -I

Analytical Reasoning Skills-II

Verbal Skills-I

Verbal Skills-II

Quantitative Skills-I

Quantitative Skills-II

The exam might be Objective/Multiple Choice Questions and every correct answer gets you 1 mark and there is a negative marking of .25. The exam is for a total of 180 marks. For more information, please visit our page at: https://bschool.careers360.com/articles/atma-exam-pattern

The exam is divided into Analytical, Verbal and Quantitative skills.

Under Analytical reasoning skills, your aptitude skills will be checked. The most important topics that you need to focus here would be:

Odd Man Out

Relations

Number Series

Data Sufficiency

Syllogism

Coding and Decoding. As this is the most tricky section, this needs a lot of practise. Solve as many sample papers as possible to get the hang of the section. Make notes when required. Regular practise can help you understand and solve the questions easily as time goes on.

Verbal Skills test your grammar and vocabulary knowledge. You should practise topics like:

Synonyms and Antonyms

Analogies

Vocabulary

Grammar

Comprehension. Read articles from time to time. Follow newspapers, magazines, and watch the news channels and browse the internet to keep yourself updated. You will need a lot of reading to help you in the comprehension section. You will need speed to help you in this section and you can achieve that only by thorough practise and reading. Take time to understand the question because most answers are interlinked.

Quantitative Skills: You should practise Arithmetic, Algebra, Geometry and Advanced Mathematics. Practise chapter by chapter and develop mental calculations. Like practise more of basic summation, subtraction, fractions and tables. Numbers, Percentage, Profit and Loss, Simple and Compound Interest, Ratio, Proportionality, Time-Distance, Time-Work, Mixtures, Averages, Partnership, Permutation and Combinations, Probability, Set Theory, Progression and Series, Line, Angles, Triangles, Quadrilaterals, Polygon, Circles, Ares, Volume, Height and Distance, Coordinate Geometry, Basic Trigonometry are few important topics. Because this section involves mathematics and takes most of your time, your focus should be on solving the problems efficiently in the beginning. Even if it takes time, practise upto perfection. Practise as many questions as you can in the conventional way. As and when you get a grip on the subject, you can go for short cuts. Memorise tables, square roots, cube roots, conversion from percent to fraction, etc. Solve sample papers on Mathematics. In the beginning, do not worry about the time it takes. As you practise, you will get the hang of the subject and it will be easier for you.