Schools need to report to the Dept of Justice’s Office of Civil Rights as far as Title IX compliance. The NCAA may aggregate the data for them, but the responsibility is the school’s.
That’s a good question about club sports. I think the answer is that schools have to show equitable access to opportunity to participate, meaning men’s and women’s clubs get the same level of access to facilities, etc. That is a different question than funding (although obviously related), which is also governed by Title IX and basically requires a roughly even split in facilities and scholarship dollars between men and women. There is a three prong test to determine compliance that is kinda complicated, but basically the idea is that athletic financial aid needs to be within a percentage point or two of the percentage of male v female athletes. Spending on facilities is becoming a new issue in this regard. I think OCR recognizes that operating the Shoe for Ohio State football and it’s hundred and ten thousand fans a week requires a different level of funding than the tennis team’s facility for a relative handful of fans, but people are starting to grumble about the absolutely insane spending on locker rooms/player’s lounges for football and men’s basketball compared to the facilities available to field hockey let’s say.
I don’t have the back ground in crew that @twoinanddone does, but my guess is that some sports operate outside the NCAA at least in part because of the Title IX requirements and the interplay with the NCAA’s Dayton Rule, which basically says that if a school is going to participate in one sport at the D1 level then it must participate in D1 for all. This is particularly important with conference membership, where the conference’s rules often have provisions about level of funding for all varsity sports. And yes, there are a handful of grandfathered exceptions to that rule, Hopkins lax being a prominent one.
Practically, the way it plays out is that the Dayton Rule prohibits UCLA say from playing basketball in D1 and wrestling in D3. I don’t know but assume that the PAC 10 rules prohibit UCLA from having a nominally D1 wrestling program that does not fund scholarships either fully or at a particular level.