I seem to recall the FREQOUT command is only accurate at 4 MHz. If you're clocking at 8 MHz, divide the value by 2 (and so forth). The command itself should work at any clock speed. Just take into account any divisor needed to achieve your 6500 Hz.

If you have Mister E PIC Multi-Calc, you can use the Timer Helper to create any frequency the processor is capable of, and at any chosen Fosc.