Hi Mubarik,
you might want to check out this article:
Regarding SAP-Adapter:
You need a S-User registered with SAP Marketplace to download the JCO and JCO IDoc libs.
You can ask the admins of the SAP system you want to connect to if they can request one for you.
The exact files of the jars are mentioned in the Adapter System Requirements guide.
Regards,
Holger