Hey,
Kindly read the Eligilbity criteria for CUSAT CAT 2014 . it says .
Pass in the Plus Two Examination of the State of Kerala or any other examination accepted as equivalent thereto with Mathematics, Physics and Chemistry as optional subjects securing a minimum of 50% marks in Mathematics and 50% marks in Mathematics, Physics and Chemistry put together.
So if you are not a pass in +2 you are not eligilbe for CUSAT CAT. but by the time of the admissions if you get passed and meets the criteria. you could have a chance. :)