My expected mark in neet 2018 is 300 in maharastra state i get mbbs govenment addmission or 15 %all india cota

With such low marks you can't get an MBBS seat.

Prepare well for next year from the beginning. This is w hat you have to do for better preparation of NEET

1. Know the complete syllabus.
2. Make a timetable. Divide syllabus in such a way that you can study it whole by November 2018.
3. Gather NCERTs and reference books to prepare for NEET 2019.
4. Start preparing by covering theory from NCERTs first, then more on same topic from reference book.
5. Solve multiple choice questions from reference books.
6. Keep taking notes throughout study process.
7. Around October, start solving previous year papers. Initially you may find them tough, but then you will get familiar.
8. Solve mock tests, sample papers also.
9. If you are appearing for board exams, then devote January-February for board exams also. Simultaneously keep revising and preparing.
10. If you find any topic tough in NEET 2019 syllabus, reach out to teachers so that you can understand that topic quickly.

With still ample time remaining, students start to get lazy and procrastinate thinking they have a lot of time. It is important for candidates to lay a groundwork for achieving their goal. In order to ensure success, a combination of hard and smart work is the key. You should start channelizing your energy towards preparing for the exam. Follow these tips to ensure that you make the best of your time in the upcoming years.