While filling the JEE Main application form, candidates must upload several documents in the prescribed format. These typically include a recent passport-size photograph, scanned signature, and valid identity proof details. Candidates must also provide information related to their Class 10 and Class 12 qualifications. Additionally, candidates belonging to reserved categories may need to upload category certificates such as SC, ST, OBC-NCL, EWS, or PwD certificates according to the guidelines provided by the National Testing Agency.