JEE Mains will be conducted 4 times a year from now starting from February to May. The first session will be held from February 23rd to 26th and the next sessions schedule will be announced later on. Every session will have a separate registration. So if you appear for February session now, you still can appear for March, April and May sessions. The best of the scores will be considered and your rank will be calculated. The examination will be held in English, Hindi, Bengali, Gujarati, Assamese, Kannada, Marathi, Punjabi, Tamil, Telugu, Urdu, Odia and Malayalam. There is no negative marking for few set of questions. This means,  there will be no negative marking in the 15 alternative questions. The candidates have to attempt 75 questions out of 90  or 25 out of questions 30 in each section of Chemistry, Physics and Mathematics.  You can apply for JEE Mains at their official website: https://testservices.nic.in/examSys21/root/Home.aspx?enc=Ei4cajBkK1gZSfgr53ImFVj34FesvYg1WX45sPjGXBoodsCAPgItCPvwv6bGBGio . You can also download the information brochure at: https://jeemain.nta.nic.in/webinfo2021/File/GetFile?FileId=1&LangId=P