A question regarding MAX II I/O supply voltage

as fas as i had understood the vccio pins too, and used them, you apply the voltage on these pins for particular io bank's

for example on a cyclone III designe here, the external sdram runs at 3,0V so the vccio pins for these io's is also connected to 3,0v to enshure this interface runs at that voltage. 3,0 V due to the 3,3V IO theme with cyclone III.

so yes it is correct what you say, but you must take care about the voltage levels VioH and VioL so choose the correct io behavioral (VTLL VCMOS ....)