Complex sentence: About 5 million people participate in the festival, majority of whom are Indian people from the states of Uttar Pradesh and Bihar, who flock into Nepal prior to the festival to circumvent the ban on animal sacrifice imposed by the Indian government.
Split into simpler sentences: About 5 million people participate in the festival, the majority of whom are Indian people from the states of Uttar Pradesh and Bihar. They go to Nepal prior to the festival to circumvent the ban on animal sacrifice imposed by the Indian government.