First and the foremost thing which we need to make clear in our mind that NMAT is a speed test which requires high level of concentration mixed with accuracy and speed. There is no negative marking in the test which lures you to attempt 100% of the paper. But, attempting the paper has to be followed by some key strategy which will help you in maximizing the score and to ace the test. Some of the key points can be summed up as..
1. The whole test duration can be classified in number of phases. In the initial phase, the level of concentration is relatively low, so, the first section in your sequence of attempt should be either a section which you are strong at, or a section which requires relatively less concentration as compared to other sections. Starting with a section you are competent in, gives you a positive flavor of the test and the much required momentum. Similarly, starting with a section/ area which requires lesser concentration levels helps you to manage the challenges during the initial phase of the test.
As time progresses, your concentration levels tend to peak and then start diluting towards the end of the exam. Thus, it is recommended to place the less engaging sections/ areas w.r.t concentration on the extremes and the more demanding ones at the centre of the time-concentration curve.
2. There is no negative marking and there are sectional time limits. Therefore, you should first attempt the questions you know and for the other questions try to make an educated guess and mark the answer.
3. You should not go with any preconceived notion of attempt as it will depend on the difficulty level of the exam. However, you are advised to keep a fine balance between effectiveness and efficiency.
4. Do not waste much time and get emotionally attached to questions and don't let the questions prick your ego. Devoting too much time to any one question can disturb the overall equilibrium and time management.
At the end of the day, please remember that the test is designed to assess your management skills though specific sections. Taking mock tests in similar formats will be helpful and help you to appropriately buck up for this challenge!