Hi Vigneswaran,
you ca first follow the below community to know more on SAP GRC;
Governance, Risk and Compliance (SAP GRC)
then you also refer the below for some additional know how;
SAP GRC Access Control: Compliant Provisioning Goes Identity Management
Exam fee, i 'm not aware of the amount. you could search from any SAP partner institutes for the same.
Best Regards,
Dinesh Rupraj