You need to be consistent everyday to study. Prepare a timetable. Follow it with discipline. 

For NEET you must first complete your Boards Portion. If you have already done with it then well and good. Then start reading NCERT of 11th and 12th standard of Physics, Chemistry and Biology. There are many reference books available for NEET Exam so don't get confused and don't refer every book. You can refer 4-5 books which consist of concepts and numericals. For physics HC Verma is best as it explains every concept in detail and also has many number of numericals to practice. For chemistry books by OP Tandon, Chemical Calculations by RC Mukherjee can be referred. 

Solve MCQs on daily basis. Organic Chemistry contains innumerable types of reaction so daily practice reactions to be thorough with them. Solve give importance to every subject equally. Focus on all three of them. Last but not the least students should take care of your health. Don't exhaust yourself too much that you can't study the other day. 

If you still have any queries feel free to ask in the comment section down below.