ETSI EN standard equivalanet to fcc 15.247 digital modulation 2.4GHz

US (fcc) states in order to be considered "digital modulation" that the 6dB BW has to be at least 500 kHz.

What is Europe (ENSI) regulation to be considered "digital modulation". Also please provide ENSI standard doc as well if available.

FCC 15.247, without checking, is about spread spectrum, which can be achieved by several modulation techniques as well as digital controlled modulation also can be narrow band, for example can FSK with digital keying be rather narrow band. ETSI EN 300 328 and EN 300 440 are both related to spread spectrum compliance in this frequency range. Check with Google.