Rome Visa:

The Schengen Visa allows tourists from around the world to go to Rome. As Rome shares is in the Italy Area, it shares a common border policy with the other countries. This means that tourist visas are not issued for individual countries such as Rome, but for the entire region. As a specific tourist visa for Rome does not exist, tourists need a Italy Visa to enter Rome for tourism. The Italy Visa allows visitors to spend up to 90 days in Rome as well as the other participating Italy countries.
To apply for a Italy Visa, you need to visit a Rome embassy or consulate in your home country. All embassies and consulates of all the Italy countries accept visa applications, but you have to apply at the diplomatic office of the main destination you plan to visit.
for more information, please visit Italy: 
https://www.schengenvisainfo.com/Italy/visa/

Official Invitation Letter:
Official invitation will be sent to attendees once after registration. The invitation letter will be sent to those who requested it through mail only.