hi Sanjay,

For CAPF preparations there are alot of books you can considered. 

Here is the list of some good books according to me that you can gove prefrences as follows :-

1.History-

brief history of modern india 

general studies paper by TMH 

ncert history

2.Polity-

ncert civics

indian polity by laxmikanth 

3.Geography-

biodiversity and environmental studies 

upsc capf practical workbook 

cbse 15 sample papers from class 12th ncert 

4.Economics-

ncert

general studies paper by TMH 

5.Science-

ncert from 6th to 12th 

6.Aptitude-

logical reasoning by Arun Sharma 

verbal&non-verbal reasoning by RS Aggarwal 

7.Current affairs-

go for the Hindu newspapers 

8.cds books also helps out in your capf exams as:-

pathfinder cds;Adhyaywar khandwar solved papers;upsc cds ;etc.

Hope this will help you out.

Also,check out some online books and courses.

Good luck.