There are various online resources offering ROMs based on Android 4.3 (also known as Jelly Bean), and all you need to do is search, confirm that there is a suitable ROM for your device and download the file. As long as you have an Android phone or tablet with root access and an unlocked bootloader, you’ll be able to install a ROM based on Android 4.3.
The best place to check is XDA-developers.com, where you will find ROMs that can be installed on a wide selection of current and older phones using tools such as ClockworkMod Recovery and TWRP.
CyanogenMod 10.2 is the most common Android 4.3 ROM, and is the latest version from the CyanogenMod team that has been building alternative ROMs since Android Gingerbread. It supports the widest number of devices, and often gets ported to less popular handsets as well, bringing easy updates to the widest number of users.
