How did you import it? What method?
Did you rip the music from a CD from within Vegas?
Explain what type of file and it’s history.
Eample: Ripped from CD in Vegas, opened in Vegas.
Eample: MP3 Download, (normalized in application other than Vegas) then opened in Vegas.
If you ripped it from a DVD within Vegas, the waveform will be identical to how it was mastered (which is usaually pretty hot). Once in Vegas you do have indivual track volume slider as well as master volume slider. If the music itself is pretty hot, almost any added volume level at either the track level slider or master level slider will cause clipping.
What you could try is to go into your preferences in Vegas and select the audio tab. Set the normalize level to -1db, then click on OK. Go out to the timeline and right click on your music waveform. Go down to switches and select normalize.
This will set the volume for the track so that the loudest peak is -1 db. Make sure that the channel slider is not adding volume. Do the same for the Master Slider. Play the track and see if it is still clipping.
Regards, Rick.