nope. after I share here, instant missing.

Can't I unlock BL in a official global rom instead of dev rom?
Thanks.

Hi, unlocking bootloader will not void your warranty. But if the device is bricked/dead during unsuccessful flashing of custom ROMs or recoveries, then it may cause issues while claiming warranty.

Nope warranty won't be voided !.  But if you've to claim warranty, flash MIUI first and then take it to service centre. If service centre found custom rom in it then they may reject it.

seems cant fastboot to flash dev rom to unlock, read it have to flash stable cn rom first, then dev rom to unlock bl

received device locked when tried to flash fastboot on cn dev.. later gonna try again

the only way to flash a china dev rom on a locked BL RN3 is thru fastboot method?
Thanks.

Apparently if there's locked device status, need to set to EDL mode, as in
http://en.miui.com/thread-235865-1-1.html
now successfully flashed the miui CN via edl mode, going to unlock it later on

flashed the china dev rom, and trying to unlock..still get the "couldn't verify device" :|

no wonder, earlier i was logged in via email on my phone ..same email used in my mi account but it doesn't link, not sure why.

now unlocked, official way
time to flash twrp, global rom and root.

well, how to mod the boot.img

edit: nvm, found it

Caution: When you ticked, Mount system partition read-only, you will get OTA updates for the Official ROM and not otherwise, as shown below:-

on this step should I tick if I want to get OTA updates for global rom? and my wifi can't be turned on.

No wonder. I have updated via OTA so my initial boot cant be used any more. Need to do again. Now downloading official rom and change the boot loader.
Update:

If you use fastboot rom need to find fastboot boot file. Cannot use the the recovery file boot img instead. It will boot loop.

Yup. thx. Find out the hard way. 

Well thus this mean any OTA update will screw us with no wifi problem?

Yeah so much hassle. Better wait major update before changing.

Now I have new problem. It will bootloop if I install super SU. 
dang it. what if unoffial way? no need to do it?

Well it is officially unlock. Now in the midst of restoring app. I try to flash the SuperSU zip file provide in the thread it will not boot. If it boot (after several tries), the super user app is no where to be seen.

Will it be possible to use GLOBAL ROM (meant for QualComm set) on AP set, which happens to be MTK model? What will happen if I apply GLOBAL ROM on MTK set?

My uncle has bought a Redmi 3 phone from China Amazon 16GB version I assume its MTK version.
He says its in Chinese and no google store etc..
He says now google play store etc....

It is possible to turn switch the OS from chinese to English? there for no need to flash rom?
even with chinese rom he can install playstore and google stuff?
-use mi appstore  to install google play store then install this normal whatsapp etc....
or does mi appstore already have whatsapp etc...

because as far as I know those voice msg for WhatsApp/WeChat doesn't store on SD Card.

max is 6-7 hours of SOT on 3g@4g mode while 7-8 on wifi. x cukup for my wife she get too used by note 2 plus zerolemon batery.. 12 hours on-wards with everything on (3g mode)