Rugby at The University of Oklahoma and Oklahoma State University
The 2020 bid package released by the IOC, did not list the specific seats required for Rugby, so the number of athletes and seating requirements are unknown.
It is assumed the field size would be similar to Soccer.
As stated in the football/soccer section of this website, there are plenty of suitable sports venues in a radius of Tulsa that is similar to the radius of the Atlanta 1996 Olympics. The most viable sites are at The University Of Oklahoma and Oklahoma State University