They are taking part in an activity called Raahgiri, and are reclaiming the streets from cars and encouraging sustainable modes of transportation. 

Read more about the initiative here: https://timesofabetterindia.com/impactful-initiatives/happy-streets

Raahgiri Day is India’s first sustained car-free citizen initiative that began in Gurgaon on Nov 17, 2013. It then moved from Gurgaon to Delhi, with the support of the New Delhi Municipal Council and the Delhi Police. It was a grand success, being held in the heart of the national capital – Connaught Place (Rajiv Chowk). From there, it spread through the country – going form large metros to small towns, as citizens decided that they needed to reclaim the streets of their city.