it would be great if you can share a picture of the PCB or inside of the amplifier, featuring this resistor which you intend to replace, or better still, a shot of the schematic where the resistor features.
Your description is lacking still. What do you mean by an input type resistor? Do you have a schematic , and can you show us where it is on the schematic ?? What does power rating 6 mean, 6 Watts ?? That power level makes little sense, given you are telling us it is an "input" resistor of a piece, suppossedly for audio use.
I have few 20-watt resistors rated from 0.5 ohms to 2.5ohms . made in Australia, very accurate. I have used these in past to connect my 4ohms rated tower speakers to my AVR's and my AVR only accepts 6ohms or 8ohms speakers.