Here is one example that I have seen of that taking 72 teams:
SEC
SEC East: Clemson, Georgia, Florida, Kentucky, South Carolina, Tennessee
SEC West: Alabama, Auburn, Florida State, LSU, Mississippi State, Ole Miss
Big 12
Big 12 North: Kansas, Kansas State, Missouri, Nebraska, Oklahoma, Oklahoma State
Big 12 South: Arkansas, Baylor, Colorado, Texas, Texas A&M, Texas Tech
Big Ten
Big Ten East: Illinois, Indiana, Michigan, Michigan State, Ohio State, Purdue
Big 10 West: Iowa, Iowa State, Minnesota, Notre Dame, Penn State, Wisconsin
ACC
ACC North: Duke, Louisville, North Carolina, Virginia, Virginia Tech, N.C. State
ACC South: Central Florida (UCF), Georgia Tech, Miami (FL), South Florida (USF), Vanderbilt, Wake Forest
Pac-12
Pac-12 North: Boise State, California, Oregon, Oregon State, Washington, Washington State
Pac-12 South: Arizona, Arizona State, Stanford, UCLA, USC, Utah
Big East
Big East North: Army, Boston College, Navy, Rutgers, Syracuse, Temple
Big East South: Appalachian State, East Carolina, Maryland, Marshall, Pittsburgh, West Virginia