What is pin type in this Metra car aftermarket radio adapter (see the attached)?
In general, those are referred to as blade contacts. They might be listed as a ‘regular’ blade contact for rectangular connectors, and they are also commonly listed as power blade contacts depending on the manufacturer and/or function of the connector. They are sometimes only described as a ‘pin’, though, for the gender type, so they can be missed in a search.
Finding the exact contact to match those in the radio adapter connector would be difficult given all of the parameters that need to align (blade width/thickness, wire gauge, etc.). They need to fit both this male housing and the corresponding female socket. The contacts are most often identified by the connector housing part number, or at least the series name.
If possible, you can try to replace both sides of the adapter connection after considering the voltage and current ratings plus the wire gauge. It is sometimes easier to find a mating pair of connectors with corresponding contacts than it is to find the original parts.