@GlideFather Thanks for your response.

We had found a fix for the problem. I don't know if this is the exact solution, but it has worked for us.

Below is the process,

1) After the records were processed, they were moved to the CMDB IRE Partial Payloads table (this refers to an incomplete data payload that, due to missing or non-existent referenced configuration items (CIs), cannot be fully processed or merged at that moment).

2) I have copied the payload from the above table and found a few errors in the payload

3) I searched for the errors in the IRE error messages and rectified them (errors were  IDENTIFICATION_RULE_FOR_RELATED_ITEM_MISSING)

4) Then, I deleted the records from the CMDB IRE Partial Payloads table (as it may cause performance degradation due to a huge number of records) and reprocessed the Import set. And, the data was transformed into the target table.