Can you upload the snaps for both of the issues you reported to understand your concern?
(Q-we can’t select the catalog items and add it to ServiceNow as Catalog.
Q-Another concern is that, even though catalog items is imported to ServiceNow it’s not properly automatically assigned to its corresponding category (though we have able to manually assign the category).
Please allow me some time to look into the issue.
If you navigate to the 'vRealize Automation Catalog' and attempt to search the catalog using the field at the top right, are you able to find the catalog item?
If you are able to find the catalog item via search, use the left column to search for 'catalog definition'. Then click 'Maintain Items'
Use the Filter to narrow down the list of catalog items available to find YOUR catalog item. You can then make any modifications you see fit.
Are you running the import jobs in correct sequence?
After performing successfull "Client Registration" the sequence should be:-
"vRealize-Automation-ImportCatalogItems" to be run after "vRealize-Automation-ImportServicesAsCategories".