The total current capacity of the 3.3V rail on ZedBoard is designed to provide 3A, the Vadj rail which also feeds the FMC interface is designed to 2A. Keep in mind that these supplies also power the Vcco banks of the FPGA which may reduce the total current available to the FMC interface. The 3.3V regulator is capable of 4A, although the circuit is optimized for 3A. The inductor used is rated for 6A so it should be ok if you exceed the 3A rating by a small margin. Typically to be safe I like to design the inductors to have a rating of 2x the max system current. Thanks Chris
