The syllabus of class 12 board exam and NEET is almost the same. Therefore, if you have been working hard in class 11 and 12, it will certainly help you in acing NEET.
First things first, prepare a study schedule and stick to it. Divide your hours between various subjects and give more time to areas in which you are weak. Practice and regular revision are vital for doing well in your board exams as well in competitive exams.
Make sure you are aware of the syllabus of AIIMS MBBS and NEET and have the right study material for your preparation. Candidates prefer NCERT textbooks as their main study material. A number of questions in the NEET question paper, especially in biology section, are from these books. There are many excellent reference books out there which you can use for your preparation. Also, go through the question papers of last ten years as they will help you understand the pattern of the exam. Practice a lot of mock tests.
Do not compromise on your sleep and take good care of your health. Work smart, work hard and study regularly. All the best!