Try this MEL script; the procedure will list the overrides for each one of your render layers:

////////////////////////////

global proc renderLayerDiagnose()
{

int $currentLayer = `getAttr renderLayerManager.crl`;
string $renderLayers[] = `listConnections -destination 1 -source 0 -plugs 0 renderLayerManager.renderLayerId`;

for ($rl=0; $rl < `size($renderLayers)`; $rl++)
{
int $id = `getAttr ($renderLayers[$rl]+".identification")`;
if ($id == $currentLayer)
{
// do your own thing here....
// e.g. this block prints out the overrides that apply to the current layer
string $overrides[] = `listConnections -destination 0 -source 1 -plugs 1 ($renderLayers[$rl]+".adjs")`;
int $index, $overridesSize;
$overridesSize = `size($overrides)`;
if ($overridesSize!=0)
for ($index=0; $index < $overridesSize; $index++)
{
print ($overrides[$index] + “\t");
print `getAttr ($renderLayers[$rl]+”.adjs["+$index+"].value")`;
print “\n”;
}
else print ("No overrides on “+$renderLayers[$rl]+"\n");
}
}
}
///////////////////////////////////////

Owen
Mayastation