Well, brother I think know it is bit too late to do this stuff!

Once the choices are locked, the portal can't be open tos shuffle. That's why it ask you twice, that you are confirm to lock the choices.

But, now I would recommend you to tell your situation to JoSAA administrater or IITR, as they can provide you an aliter way to revert th things to normal. But this I believe, is pretty difficult but you have to approach them!

Also, hope for the best.. May be you can get a chance at spot round to make things to normal

Thank You 

 At present there is not any way that you can rearrange your locked choices.More over couselling of first round also happened.This was the final list .You will be alloted seats accordig to that list only.Due to this reason they give almost ten days to make the list.And they also announce results of two mock rounds .Now there is only one way that you can avoid your undesired choices,choosing the right option among float ,slide and freeze.thank  you!!