Good afternoon.  Personal messages are stored in the users mailboxes while files shared in chats are stored in OneDrive.  There are no personal chats stored in OneDrive.

@Orazan  Thank you for the reply . Any idea on second part of query ?

Is there a way we can create separate retentions for “individual Teams Chat messages” within same archiving policy ?

 I believe if we do not have option to use same Archive Policy , alternate way would be to create a new o365 client and include Team chats alone in the backup with required retention . 

Is there other best options to achieve this requirement ? 

@Pratyush , were you able to confirm your thought about creating a new o365 client to get different retentions?

@Mike Struening Creating a new o365 client was not a viable option as this would have required to exclude all other folders from users mailbox backup ( to ensure we are not backing up same data twice) and is not that convenient . Different users would have different set of folders created under the mailbox .Could not find a better solution for this requirement . Basically ,It is either chat messages adhere to email policy or we do not archive them at all .

Appreciate you coming back to confirm the answer.