Thanks for your reply.
However, changing the region to USA or no-region-set, this should open the frequencies 1,2,3,4,5,6 as mentioned in the manual website.
Unfortunately, I have only 4 frequencies available only even after set region to the USA.
I think there is still something missing here, isn't it?
[A*****@MikroTik] /interface w60g> print
Flags: X - disabled, R - running
0 name="wlan60-1" mtu=1500 l2mtu=1600 mac-address=**:**:**:**
arp=enabled arp-timeout=auto region=usa mode=bridge ssid="****"
password="*********" tx-sector=auto put-stations-in-bridge=bridge
neither no-region-set nor USA, are showing the 6th frequencies:
USA 57.05 GHz 71.00 GHz 1, 2, 3, 4, 5, 6
as shown in the manual website https://wiki.mikrotik.com/wiki/Manual:Interface/W60G