As many as 813 of the 1,563 candidates who were earlier awarded grace marks in the NEET-UG exam appeared for a retest on Sunday, officials said.
The retest was conducted at seven centres.
There was a controversy over grace marks awarded to students to make up for the loss of time at six centres where the NEET-UG examination started late on May 5.
The Centre later told the apex court that the grace marks were being scrapped and these 1,563 students would be given an option to appear for a retest.
There were allegations that the grace marks led to inflation of marks and contributed to six of the grace mark candidates from the same centre in Haryana scoring a perfect 720 along with 61 others.
"At least 52 percent -- 813 out of 1,563 candidates -- appeared for the retest on Sunday. While no candidate appeared in Chandigarh, the number of candidates appearing from Chhattisgarh was 291, Gujarat one, Haryana 287 and Meghalaya 234," a senior National Testing Agency official said.
The Bihar police's Economic Offences Unit handed over a report to the education ministry on Saturday, following which the Centre announced that the probe into alleged irregularities in the medical entrance exam NEET-UG will be handed over to the CBI for a comprehensive investigation.
The Centre also ordered the removal of NTA DG Subodh Kumar Singh and put him on compulsory wait in DoPT till further orders.
"Based on the inputs received, 17 candidates who appeared from centres in Bihar were debarred. This takes the number of total candidates debarred from the exam this year to 110," the NTA official added.
The agency had earlier debarred 63 candidates for adopting unfair means in the exam. On Saturday, 30 additional candidates from Gujarat's Godhara were also debarred.
The NEET-UG examination was held on May 5 across 4,750 centres and around 24 lakh candidates appeared in it.
The results were expected to be declared on June 14 but were announced on June 4, with the NTA saying the evaluation of the answer sheets got completed earlier.
As many as 67 students scored a perfect 720, unprecedented in the NTA's history, with six from a centre in Haryana's Faridabad figuring in the list, raising suspicions about irregularities.
It has been alleged that grace marks contributed to 67 students sharing the top rank.
The NEET-UG examination is conducted by the NTA for admissions to MBBS, BDS, AYUSH and other related courses in government and private institutions across the country.
