I am building a salt bath furnace out of a ceramic kiln. It is a smaller one but will allow a15 inch tank.

i have the lid and one k type thermocouple.

question is I can’t seem to find any direction for connecting two thermocouples where one is for over heat of the kiln itself and one for the salt bath. 
any idea?
 

What type of ceramic kiln are you using? What type of controller does it use? There may or may not be a good way to accomplish what you describe with your current equipment, but you haven't provided enough information for anyone to answer your question. 

It will be all about the controller.  Most likely you will not have a controller that will accept two independent sensor inputs and have programmable sequences for both.  Why do you feel you need to control the kiln high temperature independent of the salt bath?  If just a high limit you may be able to get away with a second controller wired in series with the first to the SSR or contactor that is used for controlling the salt bath temperature.  Be sure to use the correct thermocouple wire and consider a ceramic shield in the kiln and SS well in the tank, molten salt fumes are quite corrosive.

Also while low temperature salt baths for tempering are reasonably straightforward, high temperature salt baths for hardening are extremely dangerous.  Your process and procedures need to be spot on to avoid molten salt volcanoes.  Hopefully you have used one under the guidance of an experienced person and aren't just relying on "You-Tube university".