There are a lot of people who celebrate Navaratri in India, and this is considered to be a Hindu festival. There are different religions that are being followed by people in India, but there are also a lot of people there who believe in Hinduism, which explains why this is considered to be a big celebration.
There are not enough details that will say if this is also being celebrated by non-Hindus, but nobody can deny that this is a big event that people would like to celebrate. This is usually celebrated for nine nights, and it will show the triumph of good over evil. Take note that this event is also being celebrated by some people who live in Nepal.