1 HP is 750W, so 6.6 kW is 8.8 HP.
The plate is telling you:
Manufacturer was Robert Birkenbeul. A google search shows that they are still in existence.
Manufacturers serial number is 152911
It's an IEC-frame metric motor, size 132 short and 4-pole (synchronous speed will be 1500 RPM at 50 Hz or 1800 RPM at 60 Hz).
Rated power is 6.6 kW, equal to 8.8 HP.
The motor can be run on 220V or 380V (nominal) 3-phase power. Although it does not say so on the nameplate, connection will be Delta for 220V and Star(Wye) for 380V.
Speed at rated power on a 60 HZ supply will be 1750 RPM.
Rated current is 23.6 Amps per phase at 220V or 13.7 Amps per phase at 380V. The Power Factor is 0.85.
The IP rating is IP54: protected against dust and splashing water.
It has insulation to class B, with a maximum permissible winding temperature of 130 degC (266 degF). It is worth mentioning that when specifying a motor to run from a VFD, Class F insulation(155 degC, 311 degF) is usually the minimum recommended.
IEC frame dimensions chart:
http://www.marathonelectric.com/docs/IECQuickReferenceDimensionalChart.pdf
