Assuming you mean in terms of judicial branch, the judicial branch's most important part is the Supreme Court. The Supreme Court's role is to interpret the Constitution and limit the powers of the other branches of government.
In a federal system, the judiciary has to deliver an additionally significant position as the protector of the constitution and the authority of conflicts between the center and states.
It serves as an autonomous and unbiased mediator between the central administration and state authorities as well as between the states.
