Thank you very much for the reply this is really helpful.
I have one more question. Is there any way i can find out where all the Nintex Workflow and Nintex Forms are used in SP2010 site collection or farm level.
You can use nwadmin.exe app:
NWAdmin.exe -o FindWorkflows [-activationsOnly]
, the . The not )
I have also attached you documentation about the nwadmin for 2010 and 2013.
If you have sharegate you can also use "pre-migration checkup": SharePoint Migration Prep: Pre-Migration Checkup | Sharegate - it should also list you all workflows in a current site.
Did you check out the workflow inventory screen? It can be accessed from within a site collection (site actions menu) or from central admin (Nintex Workflow Management) if your Nintex Workflow 2010 installation is up to date.