Download Official Android Marshmallow 6.0.1 Russia Generic 26.3.B.0.131 Stock Rom For Xperia M4 Aqua Dual E2312. This is an Original build of this Device And Here you Know Complete Guide of How to Flash.
How To Install Android MM 6.0.1 Update For Xperia M4 Aqua Dual E2312
a) Step no 1, first of all, check your M4 Aqua Device Firmware version (if you already have latest Firmware, Then Just Skipped All of These tutorials Guideline)
b) Get Latest Sony Xperia Flashtool And Install into Your PC Download From HERE
c) The Download Official Latest Marshmallow 6.0 for Sony XPERIA M4 Aqua
d) Now step to paste the ftf file downloaded in step c) to folder „Firmware“ The File is Included within the XPERIA Flashtool Folder
e) Now Run The XPERIA Flashtool, click on Installation and Choose Official Downloaded firmware, then click on ok. NOTE – if you don’t want to delete any Data of your Smartphone, just unchecked installing use data.Sin file. All Device Personal data will avail in your phone, but sometimes it will possibly reason additional troubles. So it is Good For You (and I Preferred that) to do the backup of your Useful Data, then Continue with easy And Clean Flashing and then restore your personal Phone Data.
F) Power off your phone and when Flashtool shows a pop-up window, Connect Your M4 Aqua Device to computer with Keep Holding Down volume down Key
g) after few time all Flashing Process is Complete and your Sony Device will get the brand new Rom update
Sony Xperia Bootloader Unlock
Sony Xperia Bootloader Re-Lock