The Siemens 5SL6263-6CC is a 2-pole miniature circuit breaker rated 63 A with a B tripping characteristic and a 6 kA breaking capacity at 400 V. The 6 kA SCCR at 400 V is adequate for most domestic and small commercial distribution boards; if your fault-current study shows higher available current at the panel, you'll need to step up to a 10 kA or 15 kA frame.
RoHS compliance is effective since 01 June 2013, so the part meets the EU substance restrictions for installations after that date. REACH candidate-list information is available from Siemens on request — this is standard for industrial components shipped into EEA markets. The export control classification is AL: N / ECCN: N, meaning no special license is needed for cross-border shipment under current regulations.