If you are interested in learning more about NXIVM, you might want check out the website Frank Report.  Frank Parlato is a newspaperman and blogger that worked for NXIVM as a publicist in 2007.  In 2008, he became aware of NXIVM's illegal activities.  Parlato has a website dedicated to exposing Raniere, the founder of NXIVM.  He appears to be a thorough source of information about NXIVM.

Parlato himself is in trouble with the law.  In November 2015, federal prosecutors in New York dropped a 19-count indictment charging Parlato with defrauding the IRS and the NXIVM's financial supporters, Clare and Sara Bronfman.  The Bronfman sisters are the daughters of the late Seagram's liquor magnate Edgar Bronfman.  Here is an article from Oxygen that gives more history about Frank Parlato and the charges against him.  

In this day and age, you must read everything with a critical eye.  The Frank Report appears to be the best source of information about NXIVM, but you should be aware of the charges against Mr. Parlato.  After watching the weaponization of the IRS against conservative groups back in the 2012 election, and the recently exposed corruption in the New York Attorney General's office; I would give this man the benefit of the doubt.  He may also be a victim of the globalist cabal.