Unfortunately, as of now (9th January, 2022), NCERT Biology Book is not available in Tamil Language. If you find difficulty in studying the English Edition of the NCERT Book, then you don't need to book. You can refer to your State Board Tamil Books and study from it and fortunately, 82% of NEET Questions (in 2021) were covered in Tamil Board Syllabus (Physics - 48/50, Chemistry - 38/50 and Biology - 79/100 ; Remember NEET UG 2021 had a total of 200 questions with choices included).

Source of the above mentioned statement regarding 82% NEET Question - The Hindu (Chennai) Published on 14 September, 2021

For complete details regarding NCERT Books, you may visit the link - NCERT Books 2020-21 for Class 6, 7, 8, 9, 10, 11, 12- Download All Subjects NCERT Books (careers360.com)