help In understanding rpm. rpm problem ?

Hey everybody , I have a 2011 toyota, I'm a new driver so I just noticed that when I accelerate to 60kph/35mph the rpm quickly reaches to around 2000-2100 and when I lift my foot off (not completely just enough to maintain speed ) it falls to 1500-1600
Is this normal ?

Yes. It is just your transmission upshifting. Throttle position will influence which gear you are in. You should notice that the transmission also appears to upshift when you reach around 50 mph. This is when your torque converter locks up to increase your gas mileage.