I m MBA in Finance and currently workig with KPO industry.for further study I am confuse wheather join SAP, Oracle and CISA. Cn u pls guide

I am MBA in Finance and currently working with KPO industry. For further study, I am confuse wheather join SAP, Oracle and CISA. I search a lot for CISA institute but not able to find good one. I living in Pune. fees is imp factor for taking decision, What is preferable SAP or Oracle. thank you