Will a 1968 c10 rear bumper fit a 1970 gmc 2500? ?

Yes but you hae to cut it up

Not properly - you can use a log if you wish - but don''t know if they have inspections in your country.

GO TO WIKIPEDIA, find the Chevy C/K page here: https://en.wikipedia.org/wiki/Chevrolet_C/K .  Look at which generation and body styles those vehicles fall under fall under. If the same, then yes. Or, just call any wrecking yard and ask.