That card is quite old, so any AGP card out there COULD be a candidate since todays cards will be 128 megs or more. Beware - a problem could arise when any replacement card needs a certain OS version or a certain CPU or system RAM, and so forth. I've included a BB selection, but you provided no hardware details - the details about compatibility are yours to research.
EVGA - GeForce 6200 Graphic Card - 300 MHz Core - 512 MB GDDR2 SDRAM - AGP 8x