6) During the data punching for new client activation, if the PAN number of the client is not accepted due to SEBI Debarred Entity, where I will get the details as why & against which order the client is under SEBI Debarred list?

You can check complete list of Debarred Entities along with SEBI order details from NSE & BSE Websites from following Links wherein name of such entities debarred are mentioned for your reference.