Dear Ayush
As Suraj said its absolutely correct,  and I just want to add some more information
Only if you secure high percentage in 1st year,  there is a chance of changing your branch otherwise it's very difficult.
And also if you're going to take her once again it's really seems to be very tough at that time..
So please take care if that.
If you want more information,  comment here.
All the best.

if you want change branch then you can contact with your respective administration of clg having there criteria for changing of branch.

OR

if you want to change college, then you have to give jee main once again ther is no such criteria changing college. jee main have 3 attempts only.