Sir, the 20 percentile format has been cancelled until next years IIT JEE exam as many state boards and IITs refused to follow it.
the latest format of IIT JEE is:
In pursuance of MHRD’s directions and subsequent decision of the JEE Apex Board on JEE(Main) and (Advanced) held on 25.08.2012, the JEE (Main) Examination, 2013 (hitherto known asAIEEE - Paper I) for admissions to B.E./B.Tech courses at NITs, IIITs, DTU, Delhi and other CFTIswill be held during April, 2013.The JEE (Main) (Paper I of earlier AIEEE) for B.E./B.Tech will be held in two modes, vizoffline and online (CBT). The offline examination for JEE (Main) will be held on 7th April, 2013 andthe online examinations will be held thereafter in April, 2013.The examination (Paper II of earlier AIEEE) for admissions to B.Arch/B.Planning courses atNITs, IIITs, DTU, Delhi and other CFTIs will be held on 7th April, 2013 in offline mode only.The merit list for admission to NITs, IIITs, DTU, Delhi and other CFTIs will be prepared bygiving 40% weightage (suitably normalised) to class XII (or equivalent examination) or other qualifyingexamination marks and 60% to the performance in JEE (Main) Examination.The JEE (Main)-2013 (Paper I of earlier AIEEE) will have one objective type question paper.The paper will consist of Physics, Chemistry and Mathematics. The duration of the paper will be 3(Three) Hours. The Paper II for admissions to B.Arch/B.Planning courses at NITs, IIITs, DTU, Delhiand other CFTIs will have one Question Paper consisting of Mathematics, Aptitude Test and DrawingTest as per past practice of AIEEE. The duration of the paper will be 3 (Three) Hours. Detailedbulletin is being prepared and will be published shortly.Only 1,50,000 of the top rankers in JEE (Main), which includes students from all categories (GE,OBC (NCL), SC and ST) will be eligible to appear in JEE (Advanced)-2013 (hitherto known as IIT-JEE)for admission to IITs, IIT BHU and ISM Dhanbad. Notice in this regard has been issued by the IITsystem separately.AIEEE conducted earlier by the CBSE would now be known as JEE (Main). For any clarificationregarding JEE (Main) 2013 , kindly mail your query to email@example.com
This is the latest press release by CBSE dated 7th Sept. 2012