How do I know if my truck is really an R/T?

If you have these item in your truck then you should have an RT, 395-hp, 5.7-liter Hemi V- 8, chrome 22-inch wheels, Sport models automatically become R/Ts when configured with the V-8, rear-drive, the standard cab, and the short bed.keyless entry, front and side- curtain airbags, a rearview camera, 8.4-inch touch-screen infotainment, a heated steering wheel, a seven- inch digital cluster display, a rotary gear selector, a full-length center console, power- adjustable pedals, power and heated exterior mirrors...

It should also come with the 3.92 rear end gears

You can also check the owners manual, title, history report, etc......