JEE Main signature, 10–100 KB
Sign on white paper and crop a wide strip. A square crop is the wrong shape for this file.
Do not put the passport-style photo in the signature slot.
What usually goes wrong
Keep the ink large. A miniature signature is the usual rejection on Indian exam forms.
What this page checks
JPEG between 10 KB and 100 KB, starting at 350×150 pixels. Confirm the session bulletin.