Can I sell first, and authorise the trade via e-DIS later?
No, you must authorise and unblock shares you wish to sell (via e-DIS) before placing the sell order.
For example, Ms. Leela, a non-PoA/DDPI client, wants to sell 500 shares of SBI from her demat account holdings. She will have to first unblock these shares using the e-DIS facility available on her trading platform (SELFIE/ TraderX), and only then will she be able to place the sell order.
In case the trade gets executed only for 300 shares today, she will be required to unblock the remaining 200 shares again (using the e-DIS facility), if she wishes to place another sell order.