Resolution:
The bit size of the SAP libraries depends on the bit size of the JVM. i.e. If you are using a 64-bit JVM, we should use the 64-bit JCO.

Please refer to note in SAP site in SAP Java Connector Download Page for recommended SAPJCO Bit-Architectures,  
https://websmp106.sap-ag.de/~form/sapnet?_FRAME=CONTAINER&_OBJECT=011000358700007415502002E

Kindly note that you would require a valid SAP Application Support account to access the above link. Please contact your SAP team for details.