They give a topic on spot and you have to give the GD, it is unmoderated so there are a few people who shout, or pass unethical comments on others. During my session all such people were not selected. Rather I only spoke for about 4-5 mins in the entire GD but respected everybody's argument which I think helped me bag the internship even though I did the bare minimum higher knowledge assessment that too last minute. Remember it's a discussion and not a verbal fight.