Dear Ostin, you can attempt JEE Main both through online and offline modes. You have the option to choose the mode of writing your exam. However, I just want to remind you few things while you take your decision. The OMR sheet needs to be filled manually and the bubble needs to be circled completely and it is a time taking process. It is easy to select the right option when you are selecting your answer. So just in case you have decided to go with the offline mode, please ensure that you practise enough so that you can answer all the questions manually by filling in the bubbles. Also because you cannot rewrite your answer in the OMR sheet, you need to be pretty sure of the right answer. Good luck!