Here is the list of some books you can prefer.

Intelligence Bureau Books for General Awareness


    Lucents General Knowledge
    NCERT Book from 6th to 12th.
    IB ACIO-II Central Intelligence Officer (Popular master guide) by R.Gupta

Also prefer Current affair Monthly magzines

Intelligence Bureau Books for Quantitative Aptitude

Quantitative Aptitude Test- N.K Singh
Quantitative Aptitude for Competitive Examinations- R.S.Aggarwal

Quantitative Aptitude- Kiran Prakashan

Intelligence Bureau Books for Logical/Analytical Ability

Test of Reasoning- Edgar Thorpe
A Modern Approach to Verbal & Non-Verbal Reasoning (Revised Edition)-  R.S Aggarwal

Intelligence Bureau Books for English Language-
Objective General English- R.S. Aggarwal, Vikas Aggarwal
High School English Grammar & Composition- Wren & Martin
                  IB ACIO Syllabus

Paper I (Objective Type)

General Awareness:

    Current Affairs
    Science, Business Research
    Politics
    Banking
    Economy
    Organizations etc
Reasoning:

    Similarities and Differences
    Space Visualization
    Discriminating Observation
    Problem Solving
    Analysis
    Judgment
    Relationship Concepts
    Decision Making
    Visual Memory
    Arithmetical Number Series
    Non-Verbal Series
    Figure Classification, Etc

Comprehension

Aspirants basic understanding over the English language will be judged Questions will be based on English paragraphs reasoning.
    Antonyms & Synonyms
    Word Meanings
    Closest related meanings
    Grammar
    One word substitution
    Jumbles sentences
    Idioms & Phrases
    Passage

Mathematical Ability:

   Decimals and Fractions and Relationship between Numbers
    Number Systems
    Fundamental Arithmetical Operations
    Computation of Whole Numbers
    Percentages
    Averages
    Ratio and Proportion
    Simple & Compound Interest
    Profit and Loss, Discount
    Ratio and Time
    Menstruation
    Time and Distance
    Use of Tables and Graphs
    Time and Work
Paper II (Descriptive Type):

The main purpose of this part is to check English writing skill & analytical ability. IB ACIO paper II will be conducted as Descriptive Type Test in English Language and question will be taken from English:

    Essay
    Prcis writing
    Comprehension and Business/Office Correspondence

Good Luck!

IB ACIO has intotal 1300 posts.

The exam syllabus has 2 tier.

• Tier one is of 100 marks and Tier 2 is of 50 marks.

Then there is interview as well which is of 100 marks.

• Tier one  is of 100 marks and is an hour paper. there are MCQ's divided in 4 parts and has 25 questions of one mark each. They are:

General Awareness
Quants
Logical Ability
English Language

• Tier 2 is of 50 marks and is an hour paper.

It is descriptive paper and an essay will be given and also a reading comprehension.


Book Suggested are:

• IB  Assistant Central Intelligence Officers (ACIO): Grade-II/Executive Exam Guide
• IB  Assistant Central Intelligence officer GRADE  II / EXECUTIVE 2014: Paper I & Paper II
• Intelligence Bureau ACIO Grade-II Practice Work Book (Hindi)
• Intelligence Bureau ACIO Grade-II Practice Work Book (English)

Hope this helps!!