Even today, 30 dispiriting years on. Bhopal: A Prayer For Rain plays out like a much-delayed requiem for the thousands that were killed and maimed that night. The opening credits tell us that it is ba. Presenting one of the world’s worst industrial disasters on the big screen, especially when the incident is approaching its 30th anniversary, was not easy for director Ravi Kumar through his film "Bho. A Tribute…