Have a look at the following useful links for Civil Services aspirants. (These are the NCERT books links)

Class X General Sciences (Science & Technology)

• Chapter 1
• Chapter 2
• Chapter 3
• Chapter 4
• Chapter 5
• Chapter 6
• Chapter 7
• Chapter 8
• Chapter 9
• Chapter 10
• Chapter 11
• Chapter 12
• Chapter 13
• Chapter 14

Class X Social Sciences

• Chapter 1
• Chapter 2
• Chapter 3
• Chapter 4
• Chapter 5
• Chapter 6
• Chapter 7

Class XI Physical Geography

• Chapter 1
• Chapter 2
• Chapter 3
• Chapter 4
• Chapter 5
• Chapter 6
• Chapter 7
• Chapter 8
• Chapter 9
• Chapter 10
• Chapter 11
• Chapter 12
• Chapter 13
• Chapter 14
• Chapter 15
• Chapter 16

Class XI Indian Constitution

• Chapter 1
  
• Chapter 2
  
• Chapter 3
  
• Chapter 4
  
• Chapter 5
  
• Chapter 6
  
• Chapter 7
  
• Chapter 8 difficult terms

Class XI Business Studies

• Chapter 1
  
• Chapter 2
  
• Chapter 3
  
• Chapter 4
  
• Chapter 5
• Chapter 6
• Chapter 7
  
• Chapter 8
  
• Chapter 9

Class XI Economics

• Chapter 1
  
• Chapter 2
  
• Chapter 3
  
• Chapter 4
  
• Chapter 5
  
• Chapter 6
  
• Chapter 7
  
• Chapter 8

Class XI Accountancy I

• Chapter 1
  
• Chapter 2
  
• Chapter 3
  
• Chapter 4
• Chapter 5
  
• Chapter 6

Class XI Macro Economics

• Chapter 1
  
• Chapter 2
  
• Chapter 3
• Chapter 4
  
• Chapter 5
  

Class XI Accountancy II

• Chapter 7
  
• Chapter 8
  
• Chapter 9
  
• Chapter 10

Class XII Accountancy -I

• Chapter 1
  
• Chapter 2
  
• Chapter 3
  
• Chapter 4
  
• Chapter 5

Class XII Accountancy -II

• Chapter 1
  
• Chapter 2
  
• Chapter 3
  
• Chapter 4

Class XII Human Geography

• Chapter 1
  
• Chapter 2 Chapter 3
  
• Chapter 4
  
• Chapter 5
  
• Chapter 6
  
• Chapter 7
  
• Chapter 8
  
• Chapter 9
  

Class XII Sociology (Social changes in India)

• Chapter 1
  
• Chapter 2
  
• Chapter 3

Class XII Biology

• Chapter 1
  
• Chapter 2
  
• Chapter 3
  
• Chapter 4
  
• Chapter 5
  
• Chapter 6
  
• Chapter 7
• Chapter8
  
• Chapter9
  
• Chapter11
  
• Chapter12
  
• Chapter13
  
• Chapter14
  
• Chapter15
  
• Chapter 16

Class XII Micro Economics

• Chapter 1
• Chapter 2
  
• Chapter 3
  
• Chapter 4
  
• Chapter 5
  

-NKJ