Depends what that rod has got to withstand
the rod isn’t the problem, as rightly said above you can bevel it and due to the low mass off the part being only a bar your not going to struggle to get heat into it. The 6mm plate however is a different story. Maxed out you’ll punch into it slightly but your not going to get amazing fusion. If you had more current on tap 200-250 you’d get into a spray and focus that arc on the plate letting it wet naturally on the rod. In your case that probably won’t spray so your arc will be concreted between both parts and the fusion going into the 6 will be limited. If it’s not undergoing much force it will be ok.
I have just done a bunch of 20mm bar to 6mm plate joints with no problems, these were supporting about 15kg trees 2m tall.
I did give one a severe kicking to see if it is up to the job. No problems.
I bevelled the end of the bar and welded in a deep fillet weld, using runs about 30mm long going radially around the bar.
looks attractive and is not going to fail. Done using a 180 amp Mig machine on full power.
From the man with the speech impediment, "You can't say fairer than that" The "severe kicking" is now a recognised test for bar attachment to plate but must be done with a size 9 or over and toecaps