You can't apply for B.Tech unless otherwise, you complete your basic qualification that is +2 or Intermediate. If there are any subjects you failed, first of all, you should apply for the supplementary examination and complete the subjects and get the pass certificate in the exam. After that the next year when the notification comes for entrance test you have to apply for that and get qualified with a good rank. Then only you can join in B.Tech. Otherwise, you can't be allowed to join in B.Tech. As of now, your first task is to clear your intermediate or +2.