Hi Deepu,
 
Thanks for attending this query.
 
Actually, the article is about the resources [volumes/Tape Drives] with respect to NDMP Node-scope vs vserver. This does not tell help in selecting the LUNs.
 
In the Backup windows when I click 'Content' tab to includes the resources - Only volumes are exported with SVM names. 
 
I found the workaround by manually adding the LUN to the volume.
 
Example - /svm/volumename 
 
Manually add the LUN by placing '/' , example - /svm/volumename/lunname ---- This works.
 
Thanks,
-Ashwin