Confusion regarding oberoi business

At times tej and shakti go together on business trips...den once tej said shivaye manages major chunk of Oberoi empire which he wanted om to takeover wen shivae was in hospital...if its not the same biz how can tej transfer...

If its separate then does it mean shakti also build a big business and then wat exactly is Oberoi empire...

I know these makers keep forgetting wat they said in the past but still if anyone has some clarity pls share...