Hi Prakash,
Fiori Client which is downloaded from PlayStore / App Store comes with predefined package name of the application(Fiori Client) and package should be unique for apps in the device . So only one fiori client can be downloaded and used in a device.
Other Alternative that can be a work around is to develop Custom Fiori Client using SMP 3.0 Kapsel plugin (Getting Started with Kapsel - Part 14 -- SAP Fiori Client (New in SP04) )and use different package names for different vendors. Building Custom Fiori Client is a recommended approach to use the unique capabilities of SMP 3.0 and customize the app as per the requirements of usability and branding.
Regards
Virinchy