Is your bootloader unlocked? If not then I'm afraid the only ROMs you will be able to use are old stock based (4.1.2) ROMs. Since the bootloader unlock exploit was created all development has been for TWRP and CWM.
If there is no ota available when you check then you are on the latest version and the bootloader unlock exploit has been patched..
. If there is an update available don't take it.