Hi Trisha, 

You can join Allen in class 12 for the preparation of NEET. Take more mock tests and solve the sample papers as much as you can. If you study hard while following the syllabus and tips from experts, you will definitely crack the exam. You can seek advice from candidates who already sat for the exam and cracked it for the better preparation of the exam. You can follow NCERT books for Physics, Chemistry and Biology.

Yes it best, became it's prepare for higher level

Hi there.

It would be the best to join Allen right from Class XI but in any case, if you are thinking of joining in from Class XII then I'd suggest you focus very much on your Class XI as you don't have any coaching right now.

When you get into Allen, focus on the mock test and do solve the study material questions multiple times. You will find very similar questions in the final exam of NEET.

As you wouldn't be having the guidance of a coaching in Class XI you can take help from various online platforms like YouTube and Unacademy. Only if you study with all your hard work and devotion in Class XI with Allen in Class XII then you will surely be able to crack NEET.

The following books might prove helpful in your preparation. 

First of all, for all subjects i.e Physics, Chemistry, Biology study the NCERT books cover to cover at least twice. For Biology read NCERT as many times as possible. For only the text material of Biology, you actually don't need to refer to any other book. NCERT is more than enough for biology. You might doubt this but trust me NCERT is really really enough for Biology. I can't stress more on this FACT.

For Physics, after completing NCERT complete all examples and questions from DC Pandey Objective book of physics by Arihant publishers. Revise the material as much as possible.

For Chemistry, after completing NCERT, for physical chemistry do MCQ type questions from Vibrant Academy's book of Narendra Awasthi. It is a book for JEE but for NEET you only need to do and complete the TYPE 1 questions from that book and that will be enough. You will find direct questions in NEET from this book.

For inorganic chemistry, NCERT is enough. Read it as many times as possible. The same studying principle of Biology applies to Inorganic Chemistry as well.

For organic chemistry, solve Vibrant Academy's book by MS Chouhan. This book is specifically for NEET and will be enough to score high in the organic chemistry section.

For Biology, along with NCERT solve all questions from the book of MTG NCERT at your fingertips. Solve this book and revise it as many times as possible. You will end up getting more than 300 in Biology if you have an excellent hold of NCERTs in biology and if you complete the aforementioned book.

LASTLY, your preparation would be incomplete if you don't solve previous years questions. For that refer to MTG chapter wise previous year question for all subjects i.e. Physics, Chemistry, and Biology. 

All these books are easily available in the market and online.

No one can stop you from cracking NEET if you diligently follow and solve these books as many times as possible.

Wishing you luck!