third year of bsc

[ohm]

Hi everybody,
I'm currently studing in France and preparing a BTS , a degree 2 years after baccalauréat (baccalauréat is simiar to levelA )
i would like to know if it's possible to go onto the third year of a Bsc in computer science, and if it's possible what do i write in my PS ?
i didn't find a PS that applying for entry in the third year

thanks in advance.