copy the nvmixrc  in the /etc directory as it is given as the default directory for script file
copy the ./nvmixer-reg utility in bin directory

To make this script working need to add the following lines in modules.conf after our modules alias

if sound-slot-x is our alias

then

post-install sound-slot-x /bin/nvmixer-reg -f /etc/nvmixrc -L >/dev/null 2>&1 ||:
pre-remove sound-slot-x /bin/nvmixer-reg -f /etc/nvmixrc -S >/dev/null 2>&1 ||: 