If you’ve imported data into Rapid Response, you can use the grab function to invite students to a Pre-Applicant Open Day.

Within Rapid Response, search for your students, and use the More Options dots to create an Ad-Hoc.

Under Activity Type select "Send to App", then under App List select the event you want to invite the students to.
You can also choose whether to have your Grab be:
​Static - A one time Grab of a set list of students
or
Dynamic - This list will keep looking for students that match your search criteria, and keep sending them over to your event.

The Students will automatically have an Invite record created. If they haven't already booked, they'll be added to the Invited workflow and sent a invite to the event.