I download client package (Symantec_Endpoint_Protection_12.1.4_Win32-bit_Client_EN.exe) and extra all file to a folder. From there, I zip all the files into a single zip file. I followed TECH122824 to import client package into my SEPM version 12.1.2015.2015 but the package failed with error message reads "The specified zip file is not a valid Mac package. Only Mac packages can be added in *.zip format". See screenshot in attachment.

My zip file file's extension is .zip and I don't need Mac package. How do I work around this and how do I exclude Mac package? Thanks.

You need to download the SEPM-Part1_ru4.exe  something like 

Symantec_Endpoint_Protection_12.1_RU4a_Part1_Installation_EN.exe

then extract it

you will find packages inside the SEPM folder

You need to point out the savinfo file

How to manually import client packages into Endpoint Protection Manager (SEPM)

http://www.symantec.com/business/support/index?page=content&id=TECH122824

See that thread

 MAC SEP 12.1.4 on SEPM 12.1.2

https://www-secure.symantec.com/connect/forums/mac-sep-1214-sepm-1212

James007 - there's no sav32.info file! I did the search and result none! Also, the file format .zip is allowed, there is no 'All Files' option in Files of Type selection, please advise, thanks.

Let me follow Rafeeq instruction first. BrB