No the JOSAA counselling fee of Rs 35000 is only refundable upto the 6th round of counselling. You have to withdraw till 6th round if you do not wish to take admission in the offered institutes which you have filled in your choice list. I would recommend that if you are unsure or if you make mistake in filling choice list then withdraw till 6th round and then apply for special round but remember special round is not applicable for IITs. All the best!