Generate OID using below script
1) copy the script to notepad and name it as oidgen.vbs
2) Open command prompt in Windows 7 or 8 and type below command
Ref:
http://security.stackexchange.com/questions/26516/what-oid-issuance-policies-are-appropriate-for-smartcard-and-browser-certificate/26518#26518
cscript cscript oidgen.vbs3) Copy the generated OID and assign prefix for custom class and attributes.
Ref:
http://security.stackexchange.com/questions/26516/what-oid-issuance-policies-are-appropriate-for-smartcard-and-browser-certificate/26518#26518