Hello Mahendra, 

                  After firsr round of counselling of NCHM you need to pay the seat acceptance fees and report to reporting centre.

                At the reporting centre you need to fill your choice upgration option to 'FLOAT'    and not 'FREEZE'.

            Once you fill the choice upgration to 'Float' u will be able to participate in 2nd round of counselling. Below is the link for detailed instructions for counselling.

https://nchmcounselling.nic.in/nchminfo/Handler/FileHandler.ashx?i=File&ii=84&iii=Y

 Good Luck