Inside a community centre at Mumbai's Dharavi slum, Umair Khan teaches a group of young boys the difference between good and bad touch. The 20-year-old is a community organiser with Sneha - Society for Nutrition Education and Health Action. He works with the NGO’s youth programme Ehsaas which, since 2013, has reached out to over 6,000 adolescents and youth between the ages of 15-24 in Mumbai's slums.