Government & Defence Entrance Exam

Hi Amit,
Even though the exam to be undertaken is popularly known as IAS exam, it is officially called UPSC civil services exam. The UPSC CSE consists of 3 stages: Prelims, Mains, and Interview. Getting into Indian Administrative Service is not easy considering the competition involved, but not impossible for a candidate with right attitude and approach.
UPSC (Union Public Service Commission) is the government agency responsible for selecting the right candidates for this service. Every year only around 1000 candidates are selected for all the 24 services combined. The number of candidates who applied for UPSC Civil Service Exam was about 9 lakh in 2015, out of which around 4.5 lakh candidates appeared on the exam day.
This exam is widely considered as the toughest exam in the world, considering the exam duration (extends 1 year), depth of the syllabus and the competition involved. The first stage of the exam Preliminary (objective) is usually conducted around June, while the second stage, Mains (written), is conducted around October. Those who clear Mains will have to face interview/personality test in the March-May period. The final result usually comes in June.
A disciplined and focused mind with a passion for learning and reading is the basic trait of all successful candidates. The UPSC Civil Services exam is more a test of the analytics and presentation skills along with knowledge gained by the candidate rather than a test which checks candidates mathematical or verbal skills. To clear IAS, we feel two entities as essential:
Right guidance for prelims and mains.
Right study materials and books.
Some of the important books are:
History of Modern India by Bipan Chandra (History)
Indias Struggle for Independence by Bipan Chandra (History)
History of Medieval India by Satish Chandra (History)
Indian Art and Culture by Nitin Singhania (Culture)
Geography of India by Majid Husain (Geography)
Oxford School Atlas Oxford (Geography)
Indian Polity for Civil Services Examinations by M. Laxmikanth (Polity)
Indian Economy by Ramesh Singh (Economy) or Mrunal Video Lectures
Economic Survey (Economy)
Science and Technology: Follow current affairs
Environmental: Shankar IAS Environment Book
India Year Book (Current Affairs)
Manorama Yearbook (Current Affairs)
For CSAT:
CSAT Paper 2 Manual by TMH or CSAT-II Arihant (CSAT Paper 2)
Analytical Reasoning M. K. Pandey (CSAT Paper 2: Analytical Reasoning)
Verbal & Non-Verbal Reasoning RS Aggarwal (CSAT Paper 2: Reasoning)