Dear Srinisha
No, you don't have to register or pay again for round-2 if you have already done them in round-1 for Online All India Quota or Deemed/Central Universities UG Counseling-2019 but have to make fresh choices again for round-2 by using the same login credential as used in round-1.
Before going for further steps, kindly read the instruction carefully given in links below Https://medicalcounseling.nic.in/UGCounselling/Documents/SchemeUG2019.pdf
Https://medicalcounseling.nic.in/UGCounselling/Documents/FAQMCCUG2019.pdf
Hope it helps you.
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