As of there is no update on NEET being held twice. And to be eligible for NEET, you should have completed your 12th, passed in all subjects and secure a minimum aggregate of 50% in Physics, Chemistry and Biology. It is 50% for General Category, 45% for PWD and 40% for OBC,SC,ST. Now if you belong to OBC Category, the Category you belong to should be also listed in the Central OBC list. Or else you will be considered as General Category and so you have to secure a minimum aggregate of 50% in Physics, Chemistry and Biology. This 50% is inclusive of the Theory and Practical marks scored in Physics, Chemistry and Biology collectively. You needn't score 50% in Physics, 50% in Chemistry and 50% in Biology separately. You need an aggregate of 50% or 40% depending on your Category as an aggregate in Physics, Chemistry and Biology. And along with Physics, Chemistry and Biology, you should also have studied English as one of the core subjects in your 12th. No date has been fixed yet. It is still yet to be released officially by either NTA or MHRD. NTA is the exam conducting authority of NEET. Now the HRD Minister did conduct a webinar to take the opinions of Students, teachers and Parents regarding the CBSE date sheet, NEET and JEE examination syllabus. But no dates have been announced yet. Ideally the official notification for NEET is released in December. NTA has not released any official information regarding NEET 2021 yet. It might be scheduled for May 2021 but the application process might begin a month or 2 late may be in January. So please wait to hear from NTA or MHRD regarding this.