Hello Santosh,
As Nicole has mentioned you need to link activities of the Invitation category to activity types of the categories Status Change, Qualifying Event, and Questionnaire.
This can be done in the IMG area: "Link Activity Types with Referencing Activity Types"
For further information you can see the documentation for these in the IMG and also the below links will more detail:
https://help.sap.com/saphelp_globext607_10/helpdata/en/49/198643851214cde10000000a42189b/content.htm
Regards,
Keith