That is a just a Ruger 10/22 (.22 cal rimfire), with an aftermarket stock kit to make it look like an AR-15 style rifle.
Something like this
ProMag Archangel Conversion Stock for Ruger 10/22 Polymer Desert Tan
This is a standard Ruger 10/22
Ruger® 10/22® Carbine Autoloading Rifle Models