How much voltage and current can a Arduino uno digital input sink?
You have 2 different questions here. First one can be answered by google search, it is literally the first result.

The Arduino Uno uses the atMEGA328 microcontroller, which has an absolute maximum rating of 40 mA source or sink per GPIO. Also, the total current through the supply or ground rails (i.e. the total of all current OP wants the GPIO pins to sink, or source) is rated to a maximum of 150 200 mA.

And you should not apply more than 5V.

Regarding second question, Google can help again.

 

Vin is your 24V from controller, Vout is your Arduino digital 5V input. With that established, use voltage divider formula to calculate R1 and R2 values. I hope you can do that?
That being said, I am disappointed, because I feel like you have put 0 effort into researching this.