You biggest concern should not be frame rate. It should be, will your equipment support the disc you want to purchase. In the DVD days, I had (still have) an Oppo that would
play anything (any format, any region). It was awesome.
As I said before, the frame rate has more to do with the source country (and the AC frequency they use) than whether its NTSC or PAL.
Typically, with Blu-ray, you don't have to worry because most are either NTSC or PAL. This is nice because most often they will be in the original frame rate of the source material. You have to be careful, though, because (like everything) there are exceptions. There is one TV show I like where I purchase the UK versions because they are in the original frame rate, where as the US ones are converted to 23.976 (it's a British show).
When I choose a disc, I try to get one that's in the original frame rate, aspect ratio, etc., regardless of what that is.
Found this on Wikipedia and thought it might help you:
"The term PAL was often used informally and somewhat imprecisely to refer to the 625-line/50 Hz (
576i) television system in general, to differentiate from the 525-line/60 Hz (
480i) system generally used with NTSC. Accordingly,
DVDs were labelled as PAL or NTSC (referring to the line count and frame rate) even though technically the discs carry neither PAL nor NTSC encoded signal. CCIR 625/50 and EIA 525/60 are the proper names for these (line count and field rate) standards; PAL and NTSC on the other hand are methods of encoding colour information in the signal."