There is no caste involved in this case.
Eve teasing is a big problem in Delhi. What happened with this girl is horrid and I still can’t read whole news. Very disturbing. Not sure, why this couple decided to travel by this bus?
They got on this bus because they had been unable to get a taxi to take them to the district where they lived (no driver wanted to take them that far). The bus pulled up at the empty taxi stand where the couple were standing, and the couple asked if the bus could take them, and the people on the bus agreed.