Hello Anu

First thing is you have sufficient time for preparation to crack this exam. The approach shuold be right. Plus you have to work very hard to achieve your goal that is to secure a MBBS seat in top government college.

Start from the NCERT which will make your base. You have to make your foundation strong. 

Physics : NCERT 11,12 . When you are done with this you can go for H C Verma and Universal for question practice. Dont forget to solve previous year question at any cost , which will make you understand the nature of question.

Chemistry: NCERT 11,12 . For some past year the Chemistry paper was easy to solve but it can change any time. The NCERT are really helpful , all the examples, diagrams,  reactions , all are important. You have to read atleast 3-4  times. After this you can solve previous year questions, D C Pandey, MTG NCERT @FINGERTIPS.

Biology: NCERT 11,12 . This are the bibles for biology. Just read as many times as you can. Each and every line is important. Observe all the diagrams carefully. Dont mug up. You can practice previous year question, MTG NCERT@FINGERTIPS.

This are enough to crack the exam. Follow religiously. Make a proper time table. Allot equal time to each subject. Focus on your weak areas.

For more information, you can visit below link: 

https://learn.careers360.com/medical/neet/

Thank you