"Title II" in this context refers to Subchapter II of 47 U.S.C. Chapter 5. 47 U.S.C. is the Communications Act of 1934, the act of Congress that established the FCC, and Chapter 5 is the part that deals with "Wire and Radio Communications."
If you want to know what this law empowers the FCC to do, you can read the statute yourself. Or, if that's too difficult, you can also use your access to the internet to look up more accessible sources, such as Wikipedia's "Common carrier" article.