G'day Peter T,Most ofn the Eastern flutes and whistles we see, here in Australia, are a bit dodgy in pitching ... particularly instruments from India, which seem to be accurately pitched ... in old British Philharmonic, where A = 454 Hz, not 440 Hz. This means they are a good quarter tone sharp and this is too much to make you welcome in anybody's session.
I don't know how your East Indian whistles compare. Other than that, I presume they are the deep G and A ... and these are very nicely pitched whistles to play. G allows you to easily play C and A allows a simple D. They have a nice mellow tone and don't get you stretching your fingers the way low Ds (and Overton offer a C ... and even a Bb ... below low D!) do.
Regards,
Bob Bolton