Your objective is simply to maximise your score in each section. According to the instructions in the mock test on CAT 2016 official site,
Right answer to a question : 3 marks
All questions not attempted : 0 marks
Wrong answer to MCQ : -1 marks
Wrong answer to direct answer type: 0 marks
So, every right answer is worth the same marks. So, as soon as you start a section, find the ‘low hanging fruits’.
Doing this would lead you to attempt the test in rounds.
To take an example:
Your objective of each round should be to find the lowest hanging fruits from all that remain.
Obviously, you may run out of time at any point in the table above. I.e., Your section’s 60 minutes could end at the end of/ halfway through any round. That is fine. As long as you were following this approach, you were doing the right thing.