@Gowtham Sorry, I shortened your PPD for readability 
and used the same LXMX310.PPD from the CUPS “Add printer” dialog for testing.
I found that, thanks to the *OpenUI *InputSlot PPD section, CUPS correctly resolves IPP media-source “top”, “bottom”, “by-pass-tray” and “manual”, and that these trays are visible in SavaPage.
Can you confirm you also see these trays in your Edit Proxy Printer dialog? If so, you can just select each tray and give it a name and assign the media size.