The most recent update about the loudly rumored "iPhone 6C" is that it may land as early as February or March of next year.
"iPhone 6C" Rumors
When Apple hosted their September 2015 event to introduce the "iPhone 6S" and the "iPhone 6S Plus", many were expecting a third phone that will come with that batch. With the release of the "iPhone 5C" last 2013, many people thought that releasing a budget friendly iPhone could become Apple's routine. But as the event came, no "iPhone 6C" showed up.
Furthermore, even though the "iPhone 6C" rumor originated from the "iPhone 5C", reports suggest that the "iPhone 6C" would have a lot of features that will differentiate it from the 5C and the 6S iPhones.
"iPhone 6C" Release
Rumor has it that when the "iPhone 6C" gets launched, it will be introduced together with the "Apple Watch 2". If that shall occur in February or March of next year, that will debunk theories that the next affordable iPhone is the "iPhone 7C", since it is highly unlikely for Apple to release a side iPhone first before releasing the actual flagship phone that may be the "iPhone 7". So it is more probable that the successor to the "iPhone 5C" is the "iPhone 6C".
"iPhone 6C" Design
There are talks about a plastic shell (a leaked image even surfaced online). That said, it's possible that the "iPhone 6C" will be significantly more affordable than it's flagship superiors, although probably not as affordable as a non iPhone budget phone. It is also possible to see a TouchID on the "iPhone 6C" as well as curved screen edges. If there is truth about the TouchID feature, then it would also lead to an Apple Pay support. Clearly, the description of the "iPhone 6C" will be closely similar to the "iPhone 6" or "iPhone 6S" batch, the same way the "iPhone 5C" stayed similarly close to the "iPhone 5". The "iPhone 6C" may only omit some premium feature to put a gap between the high end flagships and the affordable C model.