Do you mean you started working on the game BEFORE the start date of the jam?
Gamedevtv, is it reason for disqualification?
Literally from the jam page:
Join over 2 million students from 150+ countries and create something epic! In our annual game jam, you'll make a game in 10 days, solo or with a team - and you'll earn a free course if you submit it!
10 days = 15-25th May