Hi

That can be possible. Not all students can get seat in MBBS/ BDS in the first round of counselling itself. But in the subsequent round, if you have scored well enough to satisfy the cutoff marks then no issues, you will get the seat. The possibilities of not getting seat in the first round can be majorly due to inability of clearing or surpassing the closing marks in the colleges. Do not get disheartened, keep good and highly positive hopes. 

Best of Luck. 

Hope this helps.

Cheers!