Hello Prasad, 

Thanks for posting your query in PSC. I understand that your requirement is as below. 

When the user launches Case Manager portal(as an example), then a default work object (say T-448) should be opened up. 

Is my understand correct? If yes, refer the attached screenshot to configure the open work item and specify the work object id.

Regards,

Rincy

we don't want user to open rules. on user login we need to automatically show some instances or rules