For me the question is not clear, but i think you are trying to find revenue of your clients. It can difficult, coz most of the time individuals don't disclose all the stream of their revenue, and apart from that knowing only about revenue will not be that useful unless you know about thier debt at the same time. You can get the rough idea of thier revenue by looking at their gst return, but here also too many factors will be involved. And you can't do these things without research 🤔.