NBE seems to update their website every other day. Here is the latest update regarding documents required on the test day.
National Board of Examinations
Dated : October 30th, 2012
Subject : Testing Day Documentary Requirement
1. All candidates who have successfully registered online for NEET PG scheduled from 23rd November to 6th December 2012 are hereby informed that they have to bring the following documents at the Test Centre before appearing in NEET PG (on the date of their scheduled test day):
i. Provisional/permanent certificate of registration of MBBS qualification with MCI/SMC in original + an attested photocopy.
ii. One of the under mentioned original and valid ID document:
Voter Registration ID Card
iii. Admit Card with photo of the candidate attested by a gazetted officer.
2. Registered candidates who have obtained their primary medical qualification outside India and fulfill the eligibility criteria as mentioned in the information bulletin for NEET PG are also required to bring the aforementioned documents alongwith them on their testing day. These candidates who have passed their Foreign Medical Graduate Examination (Screening Test) and are completing their internship on or before 31st March 2012 but do not have provisional/permanent certificate of registration of their primary medical qualification with MCI/SMC can bring their original pass certificate of the Screening Test issued by National Board of Examinations on its letterhead alongwith documents at S.No.1(ii) & 1(iii) above.