Yes, you can open a Joint Demat Account at Aliceblue with a maximum of three holders. To open a Joint Demat Account you need to follow the Offline Account Opening Process. Note:
You need to provide the KYC Form along with the Account Opening Documents of all the joint holders.
All the account-related communication will be sent to the first holder only, make sure to add the correspondence address of the first holder on the Demat form.