This CM 13 ROM for AT&T Samsung Galaxy S3 is developed by XDA dev matrixzone .The ROM is functional and there are few bugs present but remember this the first release and we are sure in future update everything will be fixed.So if you want to install this ROM then follow this guide on How to Download & Install CM 13 On AT&T Galaxy S3 Android Marshmallow.
Important Read:
•Only for Galaxy S3 AT&T model no.SGH-i747.
•So Don’t try on other variants.
Don’t try this on Galaxy S3 from Sprint,T-Mobile,US Cellular and Verizon
•Custom recovery (I recommend TWRP).
Pre-Requirements:
•Make sure you have a custom recovery (TWRP/CWM) Install On your Device.
•Now from TWRP Recovery Take a full backup of your current ROM and files.
Downloads-
Download Cm13 For Samsung Galaxy S3
For more details and future updates on this ROM visit this official Xda Post
Marshmallow Gapps — Link
How to safely Download & Install CM 13 On AT&T Galaxy S3 Android Marshmallow-
• Download ROM & GAPPS
•Reboot into recovery.
• Backup your Current Rom via TWRP Recovery
•Wipe Data, Cache, Dalvik Cache
•Select Install ROM
•Install GAPPS
•After successful installation,reboot device
First boot will take 2-3 minutes time
Voilla!!! You have a lollipop in your hand now
ADS HERE !!!