Hi @ashoklak,
I'm not aware of how to accomplish that via NSO API.
I found a discussion where the accepted solution recommended doing something like this 'manually' and they explained why:
ACI - removing decommissioned servers
https://community.cisco.com/t5/application-centric/aci-removing-decommissioned-servers/td-p/2977998
Another discussion does show how to utilize an API call to accomplish something like this:
Right way to delete objects in ACI
https://community.cisco.com/t5/application-centric/right-way-to-delete-objects-in-aci/m-p/4273728#M9782
I realize neither of these is using NSO, but thought you might be able to use the knowledge regardless.
