Hi Bharath,
See definitely you are not asked to take all the four subject when you want to do is Engineering because you are not accustomed to Biology obviously. If you are an Medical aspirant then you definitely have to take Biology as a subject. It is a basic thing in all the exams not only KCET. SO don't worry about it.
Good Luck !!
Application | Exam Pattern | Admit Card | Answer Key | Result | Cutoff | Preparation Tips
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile