What is privileged documents

Sir, I have filed an application under discovery of documents in one of the case where discrimination has been done between the employees who paid the layoff package after asking the employee to leave from service. I this application I have asked the the other party to produce the settlement letter of some employees who have been paid the layoff package so that the discrimination can be proved which has been denied to me. Question: 1. Can the settlement letter/Salary slips of another employee is a privileged document or confidential document which can not be shared with the court. 2. What are the grounds employer can deny such document to share with the Court. 3. what is the approach of court in such cases when this document is required for fair trial of the case. Thanks in advance