Dear,

Floating means you will accept the seat but will wait if a better seat (in any institute) is offered in subsequent rounds. If not then you can go back to previously alloted seat.A candidate who is allotted a seat in an IIT must report at any one of the reporting centres of IITs. A candidate who is allotted a seat in an NIT+ Institute must report at any one of the reporting centre of NITs’s list. The list of reporting centres is available on the JoSAA web portal, http://josaa.nic.in

So you must visit the reporting centre to participate in further counselling process.

Hope this helps!