Question

which one of the following links all ATMs in india

Answer 1

so the question does not seem complete with options. 
The question is 

Which one of the following links all the ATMs in India ?

Indian Banks’ Association
National Securities Depository Limited
National Payments Corporation of India
Reserve Bank of India

The answer to this is 


National Payments Corporation of India

One of the key products of NPCI is National Financial Switch which connects  1,98,953 ATMs of 449 banks

Also the domestic card payment network called Rupay has been successfully developed by it.

Hope it helped

Answer 2

Founded: The National Payments Corporation of India(NPCI) was founded on 2008 for the operation of retail payments in India.

The NPCI provides a variety of services. They are,

• Rupay: A domestic card scheme.
• BHIM: Unified payment interface.
• Check truncation system
• Aadhar enabled payment system  
• National Financial Switch: A service that connects 198,953 ATMs of 449 banks in India.

Therefore, National Financial Switch by the the National Payments Corporation of India links all the ATMs in India.