National broadcasting in Japan is NHK. I also had this problem in the broadcasting field. Either the name of the company is "Nippon" or "Nihon". I did not read to me. However, it is usually "Nippon" in NHK. A few years ago, The Japanese parliament tried to unify the "Nippon". However, it would be to deny the company called "Nihon". So, it became a scrapped. Two of the name, Japanese culture is relevant. It Is that Japanese respectively think about "Japanese beauty".

にっぽん is a ancient word，but is tremendous momentum when you pronounce，for example，when the Japanese football team palying football，you wanna cherry them up，so you can say にっぽん，because have power，can scare rival，anyway，「にほん」「にっぽん」どちらも正しいです，how to use，see your mood.