Check out if the firmware is appropriate for your SAMSUNG I8260 Galaxy Core.The table contains a lot of useful information about the software. This firmware was designed for GALAXY CORE for I8260EUHAMK3 PDA version and I8260ECHEAMK3 CSC code. The software is dedicated for None bootloader type and CRC. Android Jelly Bean 4.1.2 comes with Android Security Patch Level. You should also make sure if the 1467779 changelist and 14/11/2013 build date are correct for SAMSUNG I8260 Galaxy Core.
If the specification of firmware is correct and you would like to use the CHE Entel Chile software from Chile tap on the download button. The size of all flash is 679.30MB