I'm still a beginner and thanks to some guides at xda,I was finally able to run a custom based OS on Gionee E3 with Indian firmware
Previously I was on SE W8.
This is what I followed:
1.Download Xperia HD V1 or V2(V1 has 3G on both SIM1 and SIM2,while V2 has 3G option only on SIM1).
2.Hope you have rooted and installed CWM recovery.
3.Also I hope you have downloaded the stock rom files with SP tools etc.(Indian or Chinese)
4.Now reboot into recovery and flash Xperia HD zip file on SD.
5.DONT REBOOT but POWER OFF the device.
Now the important part of all:
6.Open SP tool with all those scatter files loaded.(Search the forum on how to use SP tool).
7.Now select only two things from it.
Rest of the things will remain UNCHECKED
8.Flash the two items selected to your phone.A green circle at last will indicate a successful flash.
9.Unplug the device and press the power button.
10.Voila! Xperia HD boots up and is ready for usage.
Everything is working as per my analysis.
GPS,Wifi,Calls and Messages,Internet,Maps,Playstore etc
Although,a few bugs which can be solved
1)Data traffic i.e.,Sent/Recieved is not visible,but you can install an app called Internet speed meter to know your real time upload/download.
2)NVRAM error in Wifi,but it can be solved.Google it.