Hi Megha,
You need to attach an Event with a Macro - Macro Type Attach Event as per below. I was successfully attach an event to a ticket when a ticket was reopened.
Reopen Activity Notifiaction
Test 01 Event Detail screen,
Test 01 Macro Detail screen,
After reopened the ticket, the Event specified on the above Test 01 Macro Detail screen was attached automatically.
Hope the above settings will work on your server too.
Thank you,
Kaori