The 63 A rating holds flat up to 50 °C; above that it derates to 53.55 A at 70 °C, so a warm panel costs you about 15 % of the headroom.
That puts it above the typical 65 kA or 100 kA class for a 63 A frame — you can place this breaker closer to the service entrance without worrying about the upstream device letting through a fault it can't clear. At 690 V the capacity drops to 4.25 kA, so if your panel runs a 690 V bus, this breaker is for downstream distribution only, not the main.
The 3VA2163-5HL36-0KA0 measures 105 mm wide, 181 mm tall, and 86 mm deep — a standard 3-pole MCCB footprint that fits most DIN-rail or screw-mount panel layouts. The shunt trip occupies the auxiliary slot on the left side; verify your panel's gland-plate clearance if you're retrofitting into a tight enclosure.