There r various versions of oracle for various OS. If u use Windows then u have to determine which version of Windows and then link to Oracle site to download proper version that suits of ur installed version at home. Ur Institution may help u for this. Hope u know the all configuration though u mentioned that u r learning from NIIT. Though here is the link for ORACLE: www.oracle.com/index.html
Provided u have an account. don’t worry it is free !