....wat.the.hell. in other words, im asking, will it be able to run fallout new vegas or not? and if it does, shall i set it to lowest as possible?
Personally, I don't think that Bethesda ever tests more than a very few video cards. Whether Obsidian is as lax as that or not, I'm not certain, but their last major effort, NWN2, really had useless video card naming for requirements, so I don't think they are any more knowledgeable about hardware than Bethesda's VERY LOW standards. Honestly, however, you've gotten a lot of miles out of a five year old card that was never hugely expensive that I can recall, unless it was one of those GTO2 cards that was so easily reflashed into something better, like an XL.
In your shoes, I wouldn't gamble. I would include some sort of "full SM3" upgrade in my budget for playing FalloutNV. Same thing for anyone arriving late to the party who has never played Oblivion or Fallout 3 and is about to be bamboozled by the foolishness of naming an entire generation that has scads more junk in it than decent cards. The 6200s never could run Oblivion, or NWN2, or Fallout 3 correctly. I certainly wouldn't expect that to chane.
The 6500s were always just as bad as the 6200s. That won't change. The 6600GT ws never sold with more than 128 MBs of VRAM, and it needed the full 256 for FO3. The 6800 SE and 6800 XT often had plenty of RAM but never had enough speed. I can only imagine one card that might shift from an also-ran to being useful, which is the 6600 Vanilla, with 256 MBs of RAM on it, if there has indeed been a little bit of graphics optimization.