Need Help

I have to export my footage in format: Quicktime H.264, 25fps, 600kbps, 640x480 pix, 96 kbps audio. And then upload to FTP.

After I rendered, I found that quicktime has higher data rate (around 3,xxx kbit/s) and the file's size is very large.

I want to know how to limit the data rate of exporting file to 600kbps.

Thank for every suggestion.