Indian Asset - Demat account

We have been attempting to deal with a significant parcel of Indian shares for some time and only now has the agent mentioned the need to open a DEMAT account to enable the sale. Apprently share trading in India has long been dematerilaised. Foreign probate is secured (UK domicile case) and the shares ascertained.

Has anyone any experience on this whole process as to approaching a suitable party, preferably in this country, to open such an account as the agent appears out of his depth?

Nick Dimmock