The syllabus for KCET and JEE are almost very similar. But the questions are of different levels. The questions of JEE are slightly harder than KCET but. KCET would require you to answer a lot more questions in the limited time. As the syllabus are the same focus on getting your concepts clear and you will be able to do better. For the complete syllabus details of KCET, please refer to the following link.

Hope this helps

KCET Syllabus