Yes, ISA decides the minimum no.of frames that must be allocated for a process.
For a process that contain instructions which contain 1 memory operand, we need atleast two frames 1 for instruction, 1 for operand.Suppose the same Instruction, if it uses indirect addressing mode, then we will need another frame because of the Indirection.So we need a total of 3 frames.Like wise , the no.of frames that must be allocated to a process may increase with the indirection.
Thus Instruction Set Architecture plays a crucial role in deciding what are the minimum frames that must be allocated for a process.