JEE Mains 2020 September session was held from September 1st to September 6th. And NTA hasn't yet released the attendance list yet. But in State like West Bengal the attendance percentage has dropped considerably. Not all the registered Candidates appear for the exam in general but this time due to the fear of the Pandemic and other reasons, the number has dropped. May be in a day or 2, NTA will release the official number.