NetApp filer support both file and block access. In this case, some disks might be assigned for block access and some might be assigned for file access.
How does data ontap identify these disks? Using which can the information on objects (like disks) used for block access and file access be obtained?.
From this post it doesn't appear you understand how netapp is layed out.
Disks are created into raid-groups which in-turn create aggregates. Once you defined you aggregates you can define your volumes. Within your volumes is where you either define file based via exports/cifs or luns for block
Tools used for block are the lun commands and there are associated commands for cifs/nfs. If you don't understand this basic premise, you need to read up on it before you attempt to administer a filer