Micro presentation round is used to check your presentation skills ,confidence ,communication skills , body language .So you are needed to prepare yourself with certain selected topics but no need to prepare ppt ,you are assessed based on the way you are presenting the topic before the judges .Be well prepared with your topics.

Dear Student,

Glad to hear that you aim at Christ University for pursuing your BBA. No you don't need to prepare an PPT in micropresentation in Micropresentation round or Extempore you need to give a presentation or speak about the Topic given to you for some time and you will be evaluated on the basis of your speaking and presentation skills. Hope this might help you.