I have movies on my new ipod that is not in my library..how did this happen because i have the apple tv..

You should be able to copy them back from your iPod to your computer's iTunes library via File > Devices > Transfer Purchases, and you can then stream them from your computer to your Apple TV.

Or if they are still in the store then might show for redownloading directly on your computer's iTunes (or view downloading/streaming on your Apple TV), go to the Purchased link under Quick Links on the right-hand side of the iTunes store homepage. If they don't show there, and if the versions that you bought are still in your country's store and you haven't moved countries since buying them, then check to see if you've hidden them from the Purchased section : Hide and unhide purchases in iTunes or iBooks on your Mac or PC - Apple Support.