Both SSC CGL Tier 1 and Tier 2 exams consist of questions from 4 subjects each. In SSC CGL Tier 1 exam, Questions are asked from English Comprehension, Reasoning, Quantitative Aptitude, and General Awareness. 

Since we have to cover a large area before the examination, choosing the best study material is very important. We can start with NCERT books so that we get a comprehensive and holistic idea. Preparing notes from the study material and current affairs note preparation is also important in the case of the SSC CGL Examination. 

SSC CGL Best Books for English

1. Objective General English by SP Bakshi 
2. Competitive General English by Kiran Prakashan
3. Perfect Competitive English by V.K. Sinha
4. Quick Learning Objective General English by RS Aggarwal & Vikas Aggarwal
5. From Plinth to Paramount by Neetu Singh

SSC CGL Best Books for Maths

1. Quantitative Aptitude by Dr. R.S Agarwal
2. NCERT Maths from Grade 6 to Grade 11
3. SSC Elementary and Advanced Maths by Kiran
4. Magical Book on Quicker Maths by M Tyra
5. Advance Maths by Rakesh Yadav

SSC CGL Best Books for Reasoning

1. Modern Approach to Verbal & Non-Verbal Reasoning by Dr. R.S. Aggarwal
2. Analytical Reasoning by M.K. Pandey
3. Logical and Analytical Reasoning by A.K. Gupta
4. How to Prepare for Logical Reasoning by Arun Sharma

SSC CGL Best Books for General Awareness

1. NCERT Books of Class X, XII- History, Geography, Economics
2. Lucent General Knowledge