if somebody did not apply for first neet mds counselling he cannot participate for second round?

YES YOU CAN APPLY FOR 2ND ROUND OF YOU GET ELIGIBLE IN REVISED CUTOFF.
BUT
YOU NEED AROUND 2000-5000 RANK MAXIMUM FOR GOVT COLLEGE IN YOUR DESIRED STREAM.
AND MAXIMUM OF 15-20K RANK FOR PRIVATE/DEEMED UNIVERSITY COLLEGES FOR THE TOP BRANCHES UNDER MD AND MS COURSES.
ONLY 12,098 SEAT ARE AVAILABLE FOR MD/MS COURSE IN AIQ ROUND OF COUNSELING.
SO IF YOU WANT SEAT YOU HAVE TO BE IN TOP LIST.

AT THIS RANK YOU ARE ELIGIBLE FOR GETTING A SEAT IN DEEMED UNIVERSITY UNDER PAID MANAGEMENT QOUTA ONLY.
FOR MORE DETAILS FEEL FREE TO CONTACT US ON. 84467. 39069.
THANK YOU
PIYUSH MISHRA

I think u can apply but I am not sure

TES SHIVANI YOU CAN APPLY FOR 2ND ROUND OF COUNSELING AS IT HAS THE FRESH REGISTRATION.
DONT GO ON LAST ANSWER. YOU CAN CHECK IN MCC.NIC.IN.
FURTHER IF YOU ARE NOT ELIGIBILE NOW IN 1ST ROUND OF COUNSELING THE YOU CAN APPLY IN 2ND IF YOU GET ELIGIBLE AFTER THE REVISED CUTOFF IS OUT.
YOU NEED AROUND 200-500 RANK MAXIMUM FOR GOVT COLLEGE IN YOUR DESIRED STREAM.
AND MAXIMUM OF 2000-4000  RANK FOR PRIVATE/DEEMED UNIVERSITY COLLEGES FOR THE TOP BRANCHES UNDER MD AND MS COURSES.
ONLY 2,948 SEAT ARE AVAILABLE FOR MD/MS COURSE IN AIQ ROUND OF COUNSELING.
SO IF YOU WANT SEAT YOU HAVE TO BE IN TOP LIST.
AT THIS RANK YOU ARE ELIGIBLE FOR GETTING A SEAT IN DEEMED UNIVERSITY UNDER PAID MANAGEMENT QOUTA ONLY.
FOR MORE DETAILS FEEL FREE TO CONTACT US ON. 84467. 39069.
THANK YOU
PIYUSH MISHRA

No, You can't participate in the second round counselling if you did't register in the first round.Second round counselling is the upgradation of your college choices from the previous one you  recieved during your First round counselling. These upgradation is done only when the seat in the colleges of your preference is left empty and the student from the next rank is asked to fill it in.

Since you didn't register for the firs round you have not been assigned any college . The student below your rank would have got that seat .Letting you participate in the second round will make an irregularity and cause a problem . So, they don't allow to help the system work propperly .