how can I place tmc (traffic monitoring) points on the map?

There is an article on the wiki for TMC here. It doesn't look like a simple scheme.

If you are bringing these in from another database/source then you will need to follow the import guidelines and check license compatibility before you continue.

In the iD editor the relations applied to an element are shown below the presets and raw tags on that element. There is no TMC preset in iD so if you want to add these you will need to manually edit the relation tags according to the relevant scheme in the wiki.