Would be useful if you explain your full audio chain... I don't know the RANE 62 mixer specifically...
Have you checked ALL your leads work properly?
Might sound obvious but is the balance control for the Master on the RANE in the centre?
Does the RANE 62 plug directly in to your PC via USB for audio?
Is your RANE 62 plugged in to an internal soundcard on your PC that you are using as the OBS Audio Source?
Do you have an external soundcard that your RANE 62 connects to which in turn is connected to your PC via USB?
Have you checked the outputs from your RANE 62 in to some monitoring speakers to be sure it's not the RANE?
Does it sound fine through headphones when monitoring the master?
In OBS you should see a Stereo Output for the audio... Can you see 2 channels and is there signal to both left and right?
