You can not abel to know about that how many vaccant seats are available for you in 2nd counseling as it depend upon you that what your rank and where the 1st counselig closed it meams on which rank for that particular college. as no can tell you that how many seats are vaccant. becaus there are many seats excluding the seat given to the candidates on counseling basis these seats are known as management seat for which you have to pay the high amount of money. so no one can tel you that how many seats are available. 

I ghope this information helps you, all the best have a great future ahead.