Hi @urmimala.ghosh - thank you for reaching out to us!

Unfortunately, the endpoint "Update a Case by its caseSystemId" https://api-worldcheck.refinitiv.com/v2/cases/{caseSystemId} will not update the groupId attribute; however, the endpoint https://api-worldcheck.refinitiv.com/v2/cases/bulk/move will allow you to move 1-50 cases at a time to the group of your choice.
Regarding caseScreeningState - if what you are looking for is to enable ongoing screening (OGS), you can either use the endpoint https://api-worldcheck.refinitiv.com/v2/cases/{caseSystemId}/ongoingScreening (if you would like to enable OGS for a single case) or https://api-worldcheck.refinitiv.com/v2/cases/bulk/ongoingScreening (if you would like to enable OGS for 1- 50 cases).

So to answer your questions:

1. Kindly look into our WC1 API documentation to further understand what needs to be included within the request body schema so that the case is updated accordingly. However, is it highly recommended that you use the PATCH endpoint: "SEQ-case-update-screen: Partial update a case and screen" instead of the PUT endpoint: "SEQ-case-update: Update a case" because the latter will be deprecated in the near future. The latter only has the necessary attributes within the request body schema that are needed to update a case.
2. There is no need - kindly reference what I explained above.

If you have any further questions, please don't hesitate to reach out! I am happy to help.

Blessings,
Judith