Worldwide usage of 902-928 MHz band
First a clarification from the ITU:

G013. What is meant by ISM applications and how are the related frequencies used?
The term &quot;unregulated frequencies&quot; is not used within ITU texts. What is often meant by the term &quot;unregulated frequencies&quot; is the frequency bands for industrial, scientific and medical (ISM) applications.

Europe doesn't use the 900 MHz band, but 868 MHz (the full ISM band is 863 to 870 Mhz).
(source)
Note that some sources will refer to 868 MHz as ISM, while other will refer to the more general SRD (Short Range Device).
Further reading
ISM-Band and Short Range Device Regulatory Compliance Overview