Hi,
I have used the following circuit to read the RPM of a VR crankshaft sensor of a motorcycle engine.
A slight error in the circuit, it says "From ECM". This is actually from the crankshaft VR sensor.
The capacitor removes the DC component, if any.
The first diode is a fast switching diode, 1N4148, this removes any negative voltages.
The second diode is a 5.1V zener diode, BZX85C5V1. This makes sure that the voltage does not go above 5.1V.
Then the schitt trigger cleans up the signal to a nice square wave that can be read by an Arduino interrupt.
The wheel on my crankshaft has 12 teeth, but it does spin at up to 16,000 rpm. This means a 3.2 kHz signal at full speed.
Your engine at 6,000 rpm and 60 teeth will be producing at signal at 6 kHz. I'm not sure if this is possible for the Uno but I would imagine it is.