Hi Anjani,
You can check the SM20 log files which are written in the application server(DIR_LOGGING directory).
It's not that hard to check transaction SM20 to see what function modules are used by SAP. Basically, you are looking for function modules with name like RSAU_* such as RSAU_READ_FILE. Don't forget that if you remove audit files then you won't be able to read these files. So you can create your own custom table and schedule a simple report which will make a copy of audit records and then use this custom table in your report. Also don't forget that there is a security reason why audit records are written to file
Cheers