If you want to change the “index” title from your latex document, depending of your babel you could run in preamble.

\addto\captionsenglish{%
  \renewcommand*{\indexname}{Index of whatever I want}
}

If you are writing this in Brazilian Portuguese, you should set to your babel


\usepackage[brazil]{babel}
\usepackage{makeidx}
\addto{\captionsbrazil}{%
   \renewcommand{\indexname}{\LARGE{├Źndice dos autores}}
}

Thanks these guys from stackexchange

http://tex.stackexchange.com/questions/19268/setting-the-name-of-an-index-with-makeidx-and-adding-to-table-of-contents
http://tex.stackexchange.com/questions/8564/what-is-the-right-way-to-redefine-macros-defined-by-babel