Yup according to the latest public notice released by NTA dated on 12.10.2020, the testing agency is conducting a retest only for those candidates who are unable to attend the exam dated on 13.09.2020 due to mainly two reasons.

1 either they are in containment zone,

2 or are corona positive as on 13.09.2020

and the date of retest is 14.10.2020

and the result of both the main test and the retest ( dated on 13.09.20 and 14.10.20 respectively) will be announced on 16.10.20,

therefore NTA is conducting retest only for those student who fulfill both conditions above.

hope it helps.