Hello Prashant,

As per Syllabus  it contains subjects like Physics, Chemistry , biology ,GK and English and general ability related questions.This examination primarily consist of questions related to everything you have studied till your 12th grade.

Thus ,don't go for n number of reference books you can go with your NCERT or references you studied during School time.

Essential Tips for you Preparation

• Go throughout your materials and try to solve some sample papers online or previous year GNM papers it will help you understand the type of questions asked.
• By solving paper you can know your strong areas and weaker ones which needs more attention and you can manage time accordingly.
• Try to make proper Notes which you can refer which can save your time and energy in finding things.
• Try to make systematic timetable and give equal time to solve problems from each section.
• Most importantly get some good sleep as it will help you to focus more and you can study for long hours

Hope this will Help you!

All the Best

Thank you