Also the user who installed is privileged user, also the audit file access report is also showing that ossec is accessing files with same username who installed as follows
4 /var/ossec/queue/diff/local/tmp//*****
4 /var/ossec/queue/diff/local/var/////
4 /var/ossec/queue/diff/local/var/////**
4 /var/ossec/queue/diff/local/var///////*****
4 /var/ossec/queue/diff/local/var///////*****
4 /var/ossec/queue/diff/local/var///////*****
4 /var/ossec/queue/diff/local/var///////*****
4 /var/ossec/queue/diff/local/var///////*****
4 /var/ossec/queue/diff/local/var///////*****
4 /var/ossec/queue/diff/local/var//////*

I've never seen these messages. Could you provide more context?

The audit daemon report is printing these results. Failed syscalls. Can you explain me why I get these failed syscalls?

And also why the privileged user is appearing in these failed syscalls? Please respond

Please respond

Something on your system (selinux?) is potentially blocking unlink syscalls I guess.
The only thing I can think of in syscheckd that might call unlink is the diff checking functions.

but why do I see the same results in my file access report of aureport

Because something is blocking the syscalls? I really don't know, and I don't think I have enough information to even investigate it.

4 /var/ossec/queue/diff/local/tmp//*****
4 /var/ossec/queue/diff/local/var/////
4 /var/ossec/queue/diff/local/var/////**
4 /var/ossec/queue/diff/local/var///////*****
4 /var/ossec/queue/diff/local/var///////*****
4 /var/ossec/queue/diff/local/var///////*****
4 /var/ossec/queue/diff/local/var///////*****
4 /var/ossec/queue/diff/local/var///////*****
4 /var/ossec/queue/diff/local/var///////*****
4 /var/ossec/queue/diff/local/var//////*

These files are access by the user who installed ossec agent, without him actually accessing it.

4 /var/ossec/queue/diff/local/tmp//***** doesn't really tell me anything. I don't know what it is. The extra slashes and asterisks don't make sense to me.
Look through your audit.log maybe? Try to figure out what's going on.
What OS? Distribution? Version? Is selinux installed? Is it blocking? Are there any related errors? Are you using the diffing functionality in syscheckd? Are the files being cleaned up?