mobile

Hii guyz..
I have TWRP recovery installed on my samsung galaxy core. Earlier made my core look like lumia by changing the boot animation and all the other things like launcher etc... now when i tried emoving the boot animation .. and put a samsung bootanimation.zip in system/media(i have flashed that bootanimation4u.zip so that zips work in boot animation) the phone stuck at bootanimation then i went to recovery and tried wiping cache and dalvik cache and then by fault wiped SYSTEM too .. it resulted to a NO OS INSTALLED message when i tried to reboot ..,

Now my ques is that can i flash Lollicop rom Directly from my phone by install zip from sdcard method .. or should i first try the odin method and flash the stock rom??
will the lollicop custom rom work directly by flashing or does it require any pre-os installed..
PLEASE HELP ... any answers will be greatly appreciated..
i hve just one phone so need it to be urgently repaired...
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HELP REQUIRED...