The initial way for any candidate to crack IBPS SO exam (IT Officer) even in one month's time is sufficient practice in Online mock tests and have strong basics in English, Quant and reasoning. You don't need to read a number of books, but need to focus on your strength and clear as many online tests as possible.
You’ll get maximum questions from DBMS & Data Communication topic, so focus on this area more and try to score maximum marks in this particular section. Even a good score in English will help you grab a good overall score. There are 4 different parts (GS, English, Reasoning, Maths/DI) and you need to score good in all these sections as the cut off score for every section is different.
The professional section of IBPS SO paper includes Data Base Management System,Data Communication & Networking, Computer Organization & Structure, Data Structure & Compiler Design, Operating systems, Software Engineering, Internet Awareness.
For getting a better idea in which sections you need to focus more, you can refer to question papers of the last 5 years and practice more by solving all the questions which will definitely help you understand the pattern and identify your strong area