When to play these tunings

I do alot of playing with others and jams with others and a lot of festival jams . Now everyone is playing in keys like G-D-C- ect and jaming in the key of .. Now i can do this forever but what i want to know is there anywhere i can apply tunings  to these type of jams . Like if there playing in key of C can i play like in double C tuning or like if there playing in key of D can i use D tuning ? Do like guitars and stuff use  tunings like double C or double D tuning . I guess  you can use these with fiddles so they must use tunings . I know it's a dumb question but would like to know how to get more out of tuning playing  with others instead of the one man show idea .