That could be due to your country or we says (Rom Region).

Sometimes, it is better to download and update that phone with manually installation.

So, the thing is how you can find the latest version?

you just have to check these links for the latest roms:

http://forum.xda-developers.com/ascend-g6

or go to the official website and search about that phone with typing the exactly name and goto downloads section.for.x:

http://consumer.huawei.com/kh/support/products/downloads/ascend-g6-4g-kh.htm

P.s: if you couldn't find any new rom for your phone, another option is using CustomRoms

That could be due to your country or we says (Rom Region).

Sometimes, it is better to download and update that phone with manually installation.

So, the thing is how you can find the latest version?

you just have to check these links for the latest roms:

http://forum.xda-developers.com/ascend-g6

or go to the official website and search about that phone with typing the exactly name and goto downloads section.for-ex:

http://consumer.huawei.com/kh/support/products/downloads/ascend-g6-4g-kh.htm

P.s: if you couldn't find any new rom for your phone, another option is using CustomRoms