Question

What are the Prime minister's office, Defence minister's office and Ministries of external affairs jointly called in Delhi?

Answer 1

Friend Here is your Answer!!

The Ministry of External Affairs is largely located in SOUTH BLOCK, a building that also houses the Prime Minister's Office and the Ministry of Defence.

Its SOUTH BLOCK you are looking for.

Answer 2

The Prime minister's office, Defence minister's office and Ministries of external affairs jointly called in Delhi the Cabinet Secretariat.  

This is one of the most important part of Indian central administration where the most important decision, policies, security related matters, and external affairs are regulated.

It is a restricted area and only selected officials of highest cadre can get an entry here.