Q: iPod is not shwoing menu. Model no A1320

Hello, dsudarshan. 

The placement of the device menu has changed in iTunes 11.  To enable the classic view you will need to press Control-S for the Sidebar and Control-B for the menu bar.  I have included an article below that covers some of the changes. 

iTunes 11: Frequently used features

http://support.apple.com/kb/HT5649

In regard to the issue with your iPod nano not showing in iTunes.  This article should help you troubleshoot this issue. 

Device not recognized in iTunes for Windows

http://support.apple.com/kb/TS1538

Cheers,

Jason H.