Thank you to Dipak Bhattacharya, Michael Witzel and George Cardona for their replies to my query.

Harry Spier

On Sun, Jul 3, 2016 at 7:14 PM, Harry Spier <hspier.muktabodha@gmail.com> wrote:
Dear list members,

As far as I can see in Aufrechts edition of the Rg Veda he doesn't do word internal doubling of the consonent ch after vowels .  I did a search on gach/gacch and yach/yacch and  yuch\yucch in Aufrecht.  But another edition I looked at Max Muellers appears to do word internal doubling of consonent ch after  vowels.

What do the pratisakhyas and other authorities say about word internal doubling of ch in the Rg Veda?  Is it mandatory, optional or not done? Whats the usual manuscript practice?

Thanks,
Harry Spier