How To Transfer Shares From One Demat Account To Another Online?

There are only 2 major depositories in India- one is CDSL ( Central Depository Services Ltd) and other one is NSDL ( National Securities Depositaries Ltd). Only these two entities have the authority to open Demat account in India. Your depository participant (DP) must be a registered member of both these depositaries and either any of them to open a demat account on their client's behalf to keep securities held.