Hi Arvind,
Here are my suggestions:
1.- In DS, filter out all the Unique records so all you are left with in the Staging table are the duplicate records - the M and the S records.
2. Make sure your "Review Status" table (this is the table that you create) has these columns:
Make sure the JOB_ID column in this table match the JOB_ID in the staging table with all the duplicate records. Also, how did you generate the JOB_ID? Did you set JOB_ID = job_id()?
3. Re-run your DS job
4. Create a new "Match Review" in IS and run
5. Check your Worklist in IS for new task create after step 4 is completed.
Hope this help.