I just want to know which metals have low melting points in the range
of 400 to 600 degrees Celcius?


Interesting. Looks like there is only one actual elemental metal in the
400-600 range,
plus one "metalloid" element.

I'm assuming that the OP is asking about elemental metals and not alloys?

Hint to the OP---try a Google for "melting point of metals". It's a lot
quicker than posting here
and waiting for replies.