Can my 4th gen refurbished Ipod touch get the new IOS updates?

I just bought a refurbished 32g 4th generation ipod touch from apple, however it is stuck on iOS 6.1.6. I was expecting to be able to update it and therefore be able to get certain apps that require a higher iOS, but it says that I am up to date. I now can't get Instagram, Snapchat, and other apps I was hoping to get. Is there any way to update my ipod to the latest iOS update? I have already downloaded the new iTunes to my laptop and tried to update it from there, but it hasn't worked. Thanks so much!

Bennett