"Which language can be used to program PIC10F200/202/204/206?
Technically, you can use the MPLAB XC8 compiler; it can target these parts.
Practically, you will likely need to use assembly. The parts you're looking at all have either 16 or 24 bytes of RAM, 256 or 512 instructions worth of program memory, and a 2-level call stack. Programming in C under these conditions is extremely difficult."