Samsung Galaxy S3 has a 4.8″ 720p display. It was the first device to have a quad-core Exynos 4412 processor, with each core clocked at a maximum 1.4 GHz. It packs NFC, wireless charging capability, and the latest wireless radios. It ships with Samsung’s Nature UX interface. At the time of its launch, it ran on Android 4.0.4 ICS.
Not many devices have received Android 6.0 custom ROMs. There are some custom ROM teams which have come up with Android 6.0 ROMs for very few devices. AOSP is one such team and they have made a ROM for Galaxy S3. If you want to install it on Galaxy S3, follow the guide below.