Investors who have not submitted a physical copy of their PoA need to authorise their sell orders via e-DIS (Delivery Instruction Slip). It adds an extra layer of security while selling stocks or ETFs.
Whenever you want to sell anything from your Demat account, you will need a 6 digit TPIN from CDSL. You would have received the same on your registered mobile/email.
How do I generate a new CDSL TPIN?
How do I authorise all my holdings on Zerodha Kite?
How do I authorise my smallcase holdings?