Hey ! If you are talking about JOSAA counselling , then i am telling you the stepwise procedure for JOSAA counselling :

• Pay the acceptance fee online
• Select the reporting centre
• Report at the reporting center for document verification alobgwith all the required documents
• There , you will find a JOSAA attested form in ehich you will find three optiins , float/slide/freeze . Fill the required option and submit it at the reporting centre.

So , i hope now you are clear that it is mandatory to pay the fees before choosing float option.

Hope it helps!