Hi Srikanth,
Since your front end system runs on NetWeaver 7.4 the gateway (SAP_GWFND) and Fiori UI Add-On (SAP_UI) components would be already present in the system. The link Installation Requirements (Transactional Apps) - Setup of SAP Fiori System Landscape - SAP Library clearly specifies this fact under the section ABAP Front-End Server.
You will have to install product-specific Fiori Add-Ons on the front end and back end systems and then perform the configuration steps for the individual apps.
Regards,
Saurabh