There is not a straight forward process to forward email from a distribution list to an Office 365 Group. You would need to follow these steps in order to do that-
- Create a Shared Mailbox.
- Add the newly created Shared Mailbox as a member of the distribution list. Doing so would allow the Shared Mailbox to receive email from the distribution list.
- Set up Email forwarding in the shared mailbox to forward email to the Office 365 Group. Now there is a point to be noted here, you would not be able to do this in the Exchange Online Admin Center. You would need to use Power Shell in Order to setup forwarding to an Office 365 Group.