Hello,

Barath this is the perfect time to start preparing for NEET 2020. You can join a coaching for more number of questions, exams, and for better orientation, but that's completely optional as it depends on how clear your concepts are. If you are thorough with all the concepts or maybe if you need some help in few concepts it's better to get guidance. The main key behind cracking NEET is practicing as many questions as possible. 

For now, start chapter wise again, revise each chapter and solve as many questions as possible for each chapter from books like MTG, Arihant, etc. Give extra importance and time to  those topics that u think are little difficult or needs revision, but never miss or skip any topic thinking that it's too easy or it won't come. 

Try to finish your entire syllabus maximum by October. After that solve all the questions in whatever books you get and keep revising biology on a regular basis. By December you should start solving all previous year question papers, if possible with time constraints, so that you'll get used to the time pressure and you won't panic in your final exam. While solving questions make sure that you focus on not only the correct option, but also on why the other options are wrong as many questions in NEET can be tricky.

By February finish off with everything and keep at least 2 months for revising entire syllabus and the questions that you couldn't solve or you were confused about. 

Hope this information was helpful.

Good luck!