Writ jurisdiction is provided to HC under article 226 of the constitution and to SC under article 32 of the constitution. One can approach any court in case of violation of Fundamental rights. Hence the power is concurrent.
But High court has the power to say no to the writ. But such power is not available with Supreme Court. SC has to take decision. Further, Supreme Court can issue writs only for the enforcement of fundamental rights and not for any other purpose, that is, it does not extend to a case where the breach of an ordinary legal right is alleged. Because of above reasons the writ jurisdiction of High courts are wider than Supreme courts.