You've asked a very general question so you will get a very general answer. If you google Pillar 3 banking credit risk then you will find this definition:

You will need to refine your question to be more specific and you will most likely need to do your own research on Pillar 3 requirements. A good place to start is the Bank of International Settlements website: https://www.bis.org/ since they are the organisation that set these standards.
It is important to understand that each country sets their own Pillar 3 banking reporting requrements so I'd recommend researching on your country's supervising bank website.