Hi aspirant!

If you have acquired a seat in WBJEE counselling 1 and you have selected option "freeze" for that college then it is sure that you will get that college. However if you have opted for "float" option in counselling then you will be given colleges as per your rank which are earlier in your priority list. If you don't get any other colleges within your rank then you will get admission the college already allotted to you in the first round. You can "freeze" your college options in any round. In that case the allotted seat remains yours and there is no upgradation.

Hope this helps!

All the best!