I applied online. The process took 6 months. I interviewed at ARCI (Hyderābād) in Oct 2019
Interview
It is like the ISRO and BARC interview. There will be more than 6-panel members and the director. They will make you comfortable as much as possible. They will give you hints about the answer. They will ask more about your academic project.
Interview questions [1]
Question 1
Which process is used to analyze the size of a suspended particle