WEBENCH® Tools/CC2652R: RF range estimator

Is there any formula to calculate it

As said, if you are referring to:

you have to measure it since it's dependent of your environment. 

For car tyre what value we have to select?

As said, you have to measure what the noise is at the location. 

But is this from the tire to the inside of the car or is it from the tire to an external reader? In both cases I would assume that the required range is short and the metal in the tire/ car is the main limitation. I would make a test setup where you place one launchpad in a tire and one where you want to do the reading and check the RSSI on the link you get. If the RSSI is 6 dB or more above the sensitivity limit you have plenty of margin. The orientation of the antenna etc will impact the link budget hence it's usefull to have some margin. 

How to calculate it

As said, this is something you should test. To calculate the noisefloor at a given location is not possible.