Go through the Checklist provided to you with your first File No. and collect all your Docs...Police Clearance Certificate, IELTS certificate, Employers reference letters, and Work experience letters are required to be sent in original .CHC Delhi will return your originals when those served their purpose . Not sending your original docs will delay your application. If you don't have IELTS original ..then try to get extra copy from British council. For the remaining docs, only Notorised Attested photocopies are to be sent... Good luck.
...Bobby554