Je Tsongkhapa lived as an ordinary pure practitioner, emphasizing by his outward appearance the pure practice of moral discipline. However, his daily life was that of a Bodhisattva, and he had the  highest realizations of Highest Yoga Tantra which he never physically showed.  He was a Tantric yogi. 

He had already gained this experience many lifetimes previously, but he appeared as a Tibetan Lama for the purpose of showing clearly a special example of how to begin, make progress on, and complete the stages of the path to enlightenment.

He appeared as an ordinary human being for the benefit of his future followers. Buddha Shakyamuni also did the same. He took birth as an apparently ordinary human being, became ordained, engaged in meditation, and finally demonstrated attaining enlightenment.