As long as each indicator flashes at between 30 and 90 flashes per minute, you should be OK.
However, a car normally has only one flasher unit (which serves both sides). The only reason that it should produce different flashing rates is if there's a problem with the circuit on one side. That usually means that there's a faulty bulb. Are you sure that they're all working properly? (People often forget to check side repeater bulbs).