http://www.wes.org/required/index.asp
WES only accepts documents attested and sealed by the designated official at the institution that conducted the examination (e.g. Controller of Examination or Registrar's Offices). Attestations by individual professors, officials at affiliated colleges, or external notary publics will not be accepted.
Deputy registrar is a part of Registrar's office.I know this as mine was attested by Deputy registrar and WES evaluated it.
Good luck!