Can MBP 13 mid 2012 send audio and video through thunderbolt to HDMI? I own this model: https://support.apple.com/kb/sp649?locale=en_US

And I have an adapter thunderbolt to HDMI that works wonderfully with video, but no audio. 

Does someone has any advice on a product or the info about the capabilites of my mac to send audio AND video through thunderbolt port?
As far as I know, thunderbolt to HDMI by default provides audio.  Now, whether your adapter supports it, well that's another question.

I have used this device from Amazon Basics to supply HDMI to a TV (including audio) from a MBP and a Microsoft Surface Pro 3.  It worked with zero issues.