Hey hemant!

I do not know the exam you are talking about. But i assume it to be NEET exam , then according to MCC guidelines , the eligibility criteria for second round is as follows;

Group–I: Registered candidates who did not get any seat allotment in the 1st round.

Group-II: Registered candidates who have secured seat under reserved quota & whose 1st round of allotted seat got cancelled during the document verification on reporting for admission will be  considered for allotment of seat in the next round of seat allotment, with changed Category, subject  to availability of seat in respective category. 

Group–III: Candidates who have reported at allotted institute during 1st round of allotment and submitted willingness for second round up-gradation as Yes. 

Group- IV: Candidates who have been allotted a seat but Not Joined.

Group V: Candidates who have resigned from the allotted seat of first round at college .

So , as per your situation mentioned that you have been allotted a seat but you did not report at the reporting centre , then you lie in group  3 , and so you are eligible for second round counselling.

And now as you are eligible , you have to make fresh choices to participate in  the second round of counselling.

Hope it helps!