Tourism Lower Austria has set up an information page to assist you with your hotel booking

Tulln offers a range of hotels in different categories, bed-and-breakfast places and a youth hostel (Junges Hotel).

Tulln is very easy to reach from Vienna by train in less than 30 minutes. Vienna offers an enormous variety of hotels and places to stay in all categories.

The following link provided by Tourism Lower Austria lists a variety of special offers in Tulln for the Digital Breeding Symposium. Please note that you should book your accommodation before November 19, 2019 in order to take advantage of this block booking offers.
⇒  HOTEL OFFERS in Tulln for the DIGITAL BREEDING SYMPOSIUM