Hi mtrinath,
You can use the REST Management API service to update cluster properties with HTTP calls. Documentation on installing the REST Management API service is located at REST Management API - CA API Gateway - 9.1 - CA Technologies Documentation for your reference.
Once you have installed the REST Management API, there is a user guide with example commands to run against the service. The example URL to the documentation once it's deployed is https://<GatewayHostName>:<port>/<GatewayRESTRoutingURI>/1.0/doc/home.html
I hope that points you in the right direction. Please reply if you need any further assistance.
Sincerely,
Dustin Dauncey
Support Engineer, Global Customer Success
Email: CATechnicalSupport@ca.com
Phone: +1 800 225 5224
Outside of North America - ca.com/us/worldwide.aspx
CA API Management Community: ca.com/talkapi