Nuclear engineers research and develop the processes, equipment, and systems used to harness nuclear energy and radiation. Many of these engineers are finding industrial and medical applications for radioactive materials. For example, devices for medical diagnosis and treatment.
It’s a must without practical experience you cannot move in the career. So doing an internship will be always helpful for you to know and understand the pros and cons of the field. It will help to get the hands on skills.
GATE exam- https://gate.iitkgp.ac.in/