SushmithaGowda,
Found the option you can get to it by: "Edit Activity > Gear icon > "Reset Report Data" see attached screen-shots below. Note this will only be available for Activities that use Standard Target reporting. If your activity is using Analytics For Target (A4T) reporting you will not have this option available. In that case re-creating the activity woudl be the best way to start fresh. See screenshots below showing all of this.
If this satisfies your query please like, mark as helpful and mark as answer. Otherwise lets keep the conversation going. Hope you have a wonderful day.
Screen-shot 1 showing how to re-set data in reporting:

Screen-shot 2 showing how to re-set data in reporting:

Screen-shot 3 showing that the option will not be available for A4T enabled activities:

Mihnea Docea | Technical Support Consultant | Customer Experience | Adobe | (:: 1 (800) 497-0335
