Is there any devices or any way in how to retrieve deleted emails and chats on gmail?

Nope, you're out of luck.
As with other webmail services, once messages are deleted they are GONE for good..

For deleted emails, if you want to retrieve one that you have deleted through the inbox only, and not in the bin, and also is less than 30 days from the date you deleted it, you should be able to have it in your gmail bin.

Chats are not saved unless you choose to do so.