For about 12 lakh students aspiring to become engineers, the Central Board of Secondary Education is organising the largest exam of our country the JEE (Main) on 2 April in offline mode and on 8- 9 April in online mode. Through this the top 2.2 lakh students will get a chance to appear in the JEE (Advanced) scheduled on 21 May. 
The JEE Main however will have a separate merit list for admission to the NITS, IIITs, GFTIs and some deemed universities. There is no weightage to board marks unlike last year where 40 per cent was given to class+2 board marks and 60 per cent to JEE Main score. Also, this year only those students who had a valid Aadhar card could apply and the number of attempts remains three. 
A serious aspirant ideally must have completed the syllabus by now. Analysis of each paper is important to check the mistakes and to avoid repeating them in the actual exam. For students who are repeaters, may join a crash course for topic wise revision along with several mock tests, else they should have a systematic revision plan involving rigorous testing concept wise/chapter wise along with several mock tests from reliable sources as per current pattern.
Sometimes the right strategy and time management play a vital role in deciding the rank for an aspirant. So, one must be quick enough to adapt to the level of the paper and act promptly. 
One basic approach could be not to give full time in one go to a particular instead allocate some time so that one could review this subject again. For a three hour paper with three subjects, generally students tend to give one hour each. It is advisable that they give 40-45 minutes in attempting questions from any one subject they feel confident and move on to second subject and then to the third. In the remaining time the unsolved questioned may be reviewed. This would help in increasing the attempting rate. However, students may develop their own strategy based on their preferences.
Clearing JEE (Main) is not a difficult task. Systematic approach towards its preparation along with a proper revision plan will help students get admission into one of the top National Institutes of Technology. Looking at the previous year trends, there is generally one question from each of the chapters in physics, chemistry and mathematics. So, selective study is not advisable. Given the weightage, in mathematics you can expect more questions from calculus and algebra. In physics, one can expect more questions from mechanics and electromagnetism. In chemistry there could be more questions from physical and organic chemistry.
Always attempt theoretical/ fact based questions first and then questions which require calculation. It’s human nature that if you attempt a few confident questions in the beginning then you feel loaded with positive energy which increases your efficiency and speed for the rest of the paper. It is advisable to avoid lengthy numerical questions in the first 10 or 15 minutes of the exam.