CBSE 12th

Do not waste your precious time in vacations or other lazy things like that. The time period after 12th exams is decisive. You must be preparing for some of the most popular Entry Level Tests for either, engineering, Medical or even Bank & Railways Exams.
Do not take any of these exams lightly. Your Future and Career depends on your performance in these exams.
I'd suggest you to start giving 5-6 hours to your preparation each day including 10 min break on top of every hour. Keep looking for new ways to solve given problems and easier theory concepts so that you can answer each and every question in the exam, efficiently. Take help. It's really important that you take help from Tutors, Friends and School Teachers while you prepare. Although, it's not easy to reach your Friends and School Teachers everytime you need some help. You might look into the option of getting into Test Coaching or Get Tuitions but it won't be much of help for you because it's not Self-paced. Also, it doesn't give you much of a choice to select/change your tutor once you've joined their class.
What you can do to improve your pace & quality of preparation for Entry Tests is taking help from Online Tutors.
1- Online Tutors are your private tutors, it is completely self-paced.
2- Online Tutors are rated, ranked and reviewed and you can decide on your own to learn with which tutor. The choice is always yours to make.
3- Online Tutors are available 24*7 to resolve any and all doubts for you. You can Chat with them before taking a Session(Class).
4- It's convenient because you don't need to travel to do Preparation with your Online Tutors. You only require a computer with stable internet connection. You can take your Tutor anywhere with you.
Try Taking a Free Trial Class with an Online Tutors at https://user.tutstu.com/student-login-register. Just sign up with an e-mail ID and you're good to go.