Q: How can I install software 6.1 on my ipod touch 4th generation?

The 4G will go to iOS 6.1.3.

The Settings>General>Software update startes with iOS 5

What error message are you getting when yo update via iTunes? Of it says can't contact update server:

Try:

- Powering off and then back on your router.

- iTunes for Windows: iTunes cannot contact the iPhone, iPad, or iPod software update server

- Change the DNS to either Google's or Open DNS servers

Public DNS — Google Developers

OpenDNS IP Addresses

- For one user uninstalling/reinstalling iTunes resolved the problem

- Try on another computer/network

- Wait if it is an Apple problem

DNS is Domain Name Servers.  For convience, were typically use noad names for websites. However, the internet works by IP addresses. The DNS looks up the noun name and then returns the IP address.

Open DNS is one arganization that provides that service

http://www.opendns.com/about/