World Yoga Day will be marked on June 21. Yoga, a spiritual discipline, is based on an extremely subtle science which focuses on bringing harmony between mind and body. The main Yoga Day event will be held in Ranchi in Jharkhand. Prime Minister Narendra Modi will perform Yoga along with the participants. Around 30,000 people are expected to participate in the yoga event, for which security has been beefed up across the city.