Hello Fazil,
may be it is not complete solution for your requirement,but helps you
You can reference of existing SLA report in GRC system
Report Name:GRAC_CUP_SLR_RPT select from VC_GRFNREPCUST via tcode SM34
you can also add required fields ex:Approver_ID by clicking on change button(ignore warnings)
Some tables for required data in report
GRACREQ*
| GRACREJREASON |
| GRACREJREASONT |
Regards
Baithi