Raj, according to the Information Bulletin uploaded at: http://view.mahacet.org/mahacet/admin/news_document/NEET%20PG%20Information%20Brochure%202020%20-%20CET%20CELL%20DT%2010.02.2020.pdf, the bond release certificate needs to be uploaded during Online/Physical Document Uploading and Verification process. Those Candidates who have completed their Internship on or before March 31st 2018 are not eligible gor NEET PG counselling unless they can produce Bond release certificate on the day of document verification process. Now you haven't mentioned when have you completed your internship in 2018 but you will need your Bond release certificate atleast for document verification.