Can I put a 75 watt equivalent led bulb in a fixture that says 60 watts max?
Yes you can.  If you could find it, you could put 60 W (actual) LEDs in it, which would be equivalent to like 750 W incandescent.  The maximum stickers are for heat dissipation as well as electrical wiring capacity.

The only real concern is whether the dimability of the LEDs match the light switch or controller.