Gst zero rated vs nil

As per times of India, here- 16. If someone trades only 0% GST items (grains, pulses) then is it necessary to register for GST, if the turnover exceeds 20 lacs? A person dealing with 100% exempted supply is not liable to register irrespective of turnover. 17. Is it correct that person dealing exclusively in NIL rated or exempt goods/ services liable to register if turnover > 20/10 Lakh? There is no liability of registration if the person is dealing with 100% exempt supplies. So, if a person have a business of export of service (all foreign clients) it is zero rated. Does this mean if I do not want ITC, I do not have to register for GST?