Hi Jeevan,
If you want to configure your STMS like
DEV (200) ->>>> Testing DEV (100) ->>> Production 300
Suggestion from my side is to change your existing STMS configuration and make it
DEV(100) -> Prod(300)
And all the customizing changes done in DEV(200) can be moved to DEV(100) through SCC1.
If you still want to have the configuration as DEV(200) -> DEV(100) -> PROD(300), then you need to change the routes in STMS transaction.
Make sure you are logged in the domain controller in 000 client.
Regards,
Laxman