The strength of the motor's magnetic field is determined by the voltage divided by the frequency. If the frequency is increased by 20% from 50 Hz to 60 Hz, the magnetic field will have the same strength if the voltage is also increased by 20%. That is approximately what is shown on the nameplate. Operating the motor at a higher frequency with the same magnetic field strength should result in the same torque capability at the higher frequency. That should result in the same current and the same slip RPM at rated torque at 60 Hz vs 50 Hz.
The motor's synchronous speeds are 3000 RPM at 50 Hz and 3600 RPM at 60 Hz. The rated speeds are 2940 and 3540 RPM for 50 and 60 Hz resulting in 60 RPM slip at either frequency. That is another indication that the rated torque is the same for either frequency.
The power marked on the motor nameplate is the mechanical output power.
Output power (kW) = Torque (N-m) X Speed (RPM) / 9.549
The rated speed at 50 Hz is 83% of the rated speed for 60 Hz, so the rated power at 60 Hz should be 83% of 12.6 kW or 10.5 kW.
The nameplate indicates that the motor has a normal operating range of voltage variation resulting in a range of operating current variation. That would suggest a similar range of normal operating torque and power.