hii kumar
its great that you are interested in CS while in 11th have to taken bio or CS branch if have taken Bio its ok but if you would have taken the CS it would help any way, if you have free time spend some time on languages like C,C++, and during your 12th prepare for entrance exams for good universites SRM,VIT many more
regards
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile