Hi Bindu, 

If you had already registered yourself in 1st round of neet counselling and go through the verification process too then you don't neet to do that again. Yes, it automatically generated in 2nd round of counselling too.

But for 2nd round of the counselling you have to resubmitt your colleges prefrences in at the time of choice filling as it is necessary to do it again because choices of your 1st round gets voided itself and so, you have to reentre your choices of colleges.

Good luck.