The usable clearance of a 50A current clamp for Shelly EM is 10mm. Specs for NYM cable 3x6qmm denominate a diameter of 12,2mm. No chance to fit in a 50A clamp…
Alternatively you could use a Shelly 3EM with a 120A current clamp. The usable clearance of this clamp is 15mm.
It will be not possible to fit a 120A current clamp from Shelly 3EM to a Shelly EM - due to missing calibration.
Possibly, you could mount two 50A clamps of Shelly EM - one 6qmm wire through one clamp, the remaining two wires through the other clamp - and adding the current, power and energy values of both clamps.
Thanks for the rapid feedback.
Most likely will switch to 3EM but before I'll try the use of 2 CT for the 3 wires.
Thanks