This is good information about an NGO Help line called 1098.
Whenever you see a child (street child, bade ghar ka child) in ANY kind of trouble (hungry, injured, abused, dead....), just give a call to 1098 (TOLL FREE).
Tell them the problem and location of the child and move ahead. They will not ask anything else. Its a genuine organization started and supported by the Ministry of Social Welfare.... so no issues on that.
Most importantly, they are present in 55 cities so that covers most of the major cities.