Hi Smitha,
The best way to copy the report and give it a different ID is by getting the jrxml and creating it from this file.
You're correct, our best practice is not to use the same ID when copying the reports as this will create a confusion which report is OOTB and which one is not. If you simply do copy/paste in Jaspersoft console, the report will have the same ID and you will only be able to modify the name.
To avoid any confusion and follow our recommended ways, please check out:
https://docops.ca.com/ca-ppm/14-3/reporting/jaspersoft-studio-report-development/create-and-publish-jaspersoft-studio-reports
Section Create a Report with Sub Reports
It shows how to copy a report with sub reports and post to another environment, but these exact steps should are recommended to be used to copy a report and give it a different ID.
Please try it and let me know for any more questions.
Kind Regards -Nika