If I have ukulele in the tuning of F Bb C G how would I play an F, Bb, C and G as chords...
I think you mean F Bb D G, which is GCEA tuning, but one whole step lower.
If this is indeed the case, then the fingering for any chord with the new tuning will give a "real" chord one whole step lower, e.g., if you finger a G, it will really be an F; if you finger a C, it will really be a Bb; if you finger a D it will really be a C; if you finger an A, it will really be a G. Make sense?
If however, you really do mean F Bb C G, then you'll have to work it out yourself
F: 0202
Bb: 0023
C: 2245
G: 2120
Now why, if I may ask, do you want to tune your ukulele to F Bb C G?
This is the tuning tenors used back in the day (as they say).
Compared to todays popular GCEA
Sopranos were ADF#B up a step and Tenors were down a step.
It gave an Ukulele Orchestra different voices.
I think you mean F Bb D G, which is GCEA tuning, but one whole step lower.
If this is indeed the case, then the fingering for any chord with the new tuning will give a "real" chord one whole step lower, e.g., if you finger a G, it will really be an F; if you finger a C, it will really be a Bb; if you finger a D it will really be a C; if you finger an A, it will really be a G. Make sense?
If however, you really do mean F Bb C G, then you'll have to work it out yourself