Hello,
It depends on the hardwork, knowledge and preparation of the student. NCERT are the best books for preparation and for clearing the basic concepts for NEET UG exam. NEET UG is the only entrance exam (apart from AIIMS MBBS and JIPMER) for admission to medical/dental and AYUSH course so, it becomes difficult due to the high competition level.
Apart from NCERTs you should also refer to other important books for in depth knowledge and to score good marks in the exam.
You can go through the link below for the list of best books for NEET exam-

https://medicine.careers360.com/articles/best-books-for-neet

p { margin-bottom: 0.25cm; line-height: 120%; }a:link { }With sincere and dedicated efforts along with a proper study plan, you can definitely score well.
Good Luck!