FBS conferences must meet a more stringent set of requirements for NCAA recognition than other conferences:[13]

A total of at least eight active FBS members.
To be counted toward this total, a school must participate in conference play in at least six men's and eight women's sports, including men's and women's basketball, football, and at least two other women's team sports.
Each school may count one men's and one women's sport not sponsored by its primary conference toward the above limits, as long as that sport competes in another Division I conference. The men's and women's sports so counted need not be the same sport.[14]

https://en.wikipedia.org/wiki/NCAA_Division_I#:~:text=Under%20NCAA%20regulations%2C%20all%20Division,with%20less%20than%20the%20minimum.