Danuamah
It depends on what the gain structure is within the console. I hate to say it depends, but it really does.
For instance - if a board is set up properly with the pre-fader-level (PFL) of the input signal set to average 0dbv on the meter, then theoretically, you should have 10dB above 0 (Unity) on the channel fader that you can use for gain.
If that signal stays around 0dBv on the channel, it should register between -3dB and -6dB at the Master Fader Meter with the master fader set at 0dB (Unity). Most modern mixers have a "pad" on the summing buss so that the sum of all the channels doesn't saturate (distort) the master output. Mixers with 4 and 8 sub-mix busses may have -3dB or -6dB difference between the channel strip, and the sub-mix bus, then -3dB to -6dB between the sub-mix bus and the master bus.
I'll work with 32-36 traveling groups a year, and frequently, they set their portable mixers up the "old" way of the average inputing being the clip light. That's not acceptable.
Feel free to email me - if you like with any further questions.