Hi Ankur,
It is possible to use the cross-catalogue search feature in the new UI add-on to search through the product master in the SRM system (the product master has to be first created / replicated in the SRM server from ECC).
But, for the cross catalog search to work in the new UI, it is mandatory that we have the TREX or HANA database configured to the system.
The 'SRM UI Add-ON Cookbook' in the note - 1911004 mentions the steps (running a report to import product master data in TCode: /SRMNXP/CAT01).
Hope this helps
Cheers,
Yateesh