Hi Rocky Singh!
Your aspiration to become an IAS Officer and the related questions you have raised to accomplish this goal are really appreciable. To become an IAS officer you must take up UPSC examination which is going to be conducted every year.
From the current year, UPSC examination pattern has been changed for the preliminary round, civil service aptitude test(CSAT).There will be no optional subject paper in this round unlike the previous years. It will be consisting of two parts, 200 marks each. First part is to test the knowledge of current affairs (Burning topics and current trends of national, international importance), basic science (only upto class 10th level), and social studies (history, geography and civics, upto class 10th level). This paper consists of 100 questions each carrying 2 marks and are of multiple choice type.
Second paper is to test,vocabulary in English, comprehension, numerical ability, logical reasoning, verbal reasoning, quantitative ability, mathematical ability(upto class 10th difficulty level). There will be 80 questions carrying equal marks and are of multiple choice type.
Duration for each paper is two hours, and there will be negative marking for wrong answers, deducting 0.666 mark for wrongly answered only.
In the mains exam, two optional subjects have to be chosen , one each from the two list of available choices. This is will be of difficulty level upto respective bachelors' degree. You can choose English along with geography or political science. Geography will be of better choice according to my opinion. The questions will be of descriptive type. Seletion for the final interview will be based on the performance in this round.
Study material can be obtained from any training institutes offering training for these exams. For prelims(CSAT),you must read NCERT text books of 8th, 9th and 10th standard(General Science and Social Studies), Magazines like competition success review, competition vision, manorama year book are of high standard which I personally recommend.
In the personal interview, personality, attitude, analytical ability, decission making skills will be tested.
I Wish you Luck for your future.