Hi Sadaf
Could you please go to the tcode KEB2 in ECC and give your datasource name to check the detailed information about the data. This tcode will also give the delta information about the datasource and even the number of records posted in last delta.
When you need to reconcile the data for a COPA datasource, you should use KE24 tcode where all the information will be available as and how it is in your datasource.
KE24 is generic report and so it will take very long time unless you give a proper selections in the initial screen. Hence run it for one material/customer or a date.. etc.,
Try and let us know for challenges.
Regards
Karthik