According to this map published by the Washington Post, there are more people living within the lighted circle than there are outside of it.

The countries inside this circle are China, Mongolia, India, Indonesia, Bangladesh, Japan, South Korea, North Korea, Philippines, Vietnam, Thailand, Burma, Bhutan, Nepal, Malaysia, Taiwan, Sri Lanka, Cambodia, and Laos. The total population of those countries combined is an estimated 3.6 billion, about 51% of the total world population.