If your network is 50 Hz, a 12-pole motor will be 500 synchronous rpm, and an 8-pole motor will be 750 rpm. If they are induction motors, they will run slightly slower, owing to slip.
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Contact motor distributors locally, and give them some idea of the power range required and the application as well as the speed.
A 12VDC instrument motor doing 500-750rpm and pulling a few tens of mA would cost about £35GBP, whereas a 50kW motor for 415VAC doing 500-750rpm might be several £thousand.
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Motor selection requires HP, RPM, Voltage etc.
So your are silent on other two.
So AC motor with 750RPM is available.
Synchronous motors available with 500RPM and less