Hi Dadabhau,
It looks like this release is stuck in the status update for some reason. To my best knowledge if you are still seeing associated process running, I will request to go to process execution and stop that process explicitly. In case if this is not the case, I think you may consider removing this release as listed in below step.
You can remove such deployment via JMX. Please follow instruction below.
1: Get the release-id of the deployment you want to remove you can get that by opening that release and checking on URL in browser
2: Navigate to URL change the NAC-IP with your NAC/DMS IP or hostname http://NAC-IP:20203/mbean?objectname=releasecenter%3Atype%3DInfo
3: Invoke method removeRelease passing the release-id captured in step 1
Regards,
Saurabh