Although there was a lot of confusion early on after Mr. Sibal announced changes in the engineering and IIT-JEE entrance tests, now it has all become clear. The good news is students that have been preparing for the exams there is not much change in the syllabus only the format is slightly different. These are the main points related to the IIT JEE 2014-2015 Exam Format-
IIT-Main (initial screening)
The difference is that the first exam will be the IIT-Main exam and the subjects covered will be Physics, Chemistry and Biology and there are no aptitude tests in it. Additionally, the format is somewhat similar to AIEEE exam which is mainly objective. You will be sitting down for a 3 hour exam and the exam is scheduled for early or mid-April 2013, which can be given online or offline at the scheduled centres. As this is the common exam it is being conducted by CBSE for all students appearing for IITJEE. This is the initial exam that all the students have to appear for and as per the results, the top 1,50,000 students clearing it will be eligible to sit for the next round of examination which has been termed as the IIT-Advanced. The qualification for appearing for the IIT-Advanced is solely and only this Main exam and board exam marks are not being considered.
IIT-Advanced (selected students)
This round is only allowed for the top 1, 50,000 students and the subjects remain Physics, chemistry and math while the format is objective questions. It is similar to the 2012 IIT-JEE examination. Although you might have already solved the 2010 and 2011 question papers, you might still find minor changes in the format but nothing major. Sometimes reasoning section is given while in other years it is not there, likewise you might have some type of questions in more numbers while in other years, the focus is on other aspects. So this is something that cannot be predicted but of course, it is all within the syllabus.
Just like 2012, you will have 2 examinations of 3 hours each which are scheduled sometime in May 2013. This exam is specifically conducted by IIT Joint Admission Board that usually organizes and holds the IIT-JEE. As prescribed by the Supreme Court, all the students having a set cut-off marks (as in 2012 was above 35%) will be given a rank. It is not related to your board examination. The cut-off marks will be pre-decided before the examination by the Joint Admission Committee and only those getting above the cut-off will be called in for the 3rd stage which is Counselling.
With only 9600 seats for all IITs, the students have to go for counselling and based on the ranks, you will be given the admission to the appropriate IIT. It is going to be held sometime in the middle of June 2013. They have to report to the IIT for admission within a week and submit the results of the board exams. Only those in the top 20 percentile in their respective boards will be allowed to join the IIT. The boards include the state boards, ICSE and CBSE. The cut off of the percentile is relative.
So if you study well and work hard both for your boards and the IIT-JEE entrance exams, you have a high chance of joining the desired IIT.