No it is not possible to participate in 2nd round if you have not participated in 1st round. Because in 2nd rounds those students participate who either did not get what they wanted or did not get any college.

Hi there
Mist of the entrance commission asks you to attend the 1st allotment if you want to move into 2nd allotment. But it depends in the entrance commission. So its better to go for the allotment, else you might lose your admission