I bought a 3 in 1 pack of DeepCool fans, but I can't get an RPM reading for the fans, and can't control their speed. How do I fix this?

Since you have the 3 in 1 pack of fans, you are likely using the fan controller hub. Since a PWM fan header can only read the tach of one fan at a time, you would need to make sure that you have one of the fans plugged into the Fan 1 port (It is usually white).