EDIS is is the short form of Electronic Delivery Instruction Slip. As the name suggests, it is an online Delivery Instruction given to delivery shares from one's demat account. NSDL (National Securities and Depositories Ltd), one of the two major Depositories in India has introduced e-DIS) to get over pain points in POA. Instead of giving POA or a physical signed DIS slip before selling a stock from your Demat Account, you can just logon to our Rocket Trading Platform give e-DIS mandate before placing the order. To know how it works read here 

Note this facility is currently available only in Rockets. ITS (Infini Trading Solutions) users can refer here to know how to deliver shares sold from Non POA account demat account