To configure an IITR email account on a Gmail mobile app, a user must first go to their Gmail account and click add another account. They then select the Exchange and Office 365 option and enter their IITR email ID. When prompted to set up the account manually, the user enters their login details with the server set to mapi.iitr.ac.in, port 443, and SSL/TLS security. Once complete, the IITR email is accessible via the Gmail mobile app.