Hey there

I am sorry to tell you but if you have freezed your choice in josaa then you will not be able to change it anyhow. By freezing means you will not be allowed for further rounds and also you will not be able to change your branch within the same college. So students usually choose either slide or float.

Check about common mistakes in josaa

https://www.google.com/url?sa=t&source=web&rct=j&url=https://engineering.careers360.com/articles/major-mistakes-avoid-in-josaa-counselling/amp&ved=2ahUKEwiystS3nqjjAhUIVH0KHfgYATcQFjAKegQIBRAC&usg=AOvVaw2O0PLeaz15eL4SoqbwjC5q&ampcf=1&cshid=1562689132669

Good luck

Dear aspirant,
Freezing a branch or a seat means you've agreed to accept that seat which you've been allotted. In the second year if you are able to produce a pointer of above 9 then the management might think of allowing you to switch branch till then it's not possible.

If during the JOSAA coiunselling process you have frozen your alloted seat during any round of the counselling then that seat is locked for you and you are taken out of the counselling process. It is also not possible to change your alloted choice and after the completion of counselling process you will have to complete the admission formalities. Hope this helps.