HI,

See if you are studying in college under makaut wb, then it is possible to change your stream if you have above 8.5 dgpa in first year, and if you have overall 9.5 dgpa in first year you can change college which is in the same group, however rules are liable to change every year, and you need to contact with the respective college whether they will take admission or not. however you can again appear in wbjee and if you get a good score you can take admission in first  year of any engineering stream, but you have to start it again from first year.

Hello aspirant, most colleges wont allow you to change college once you get admitted into, but if you still want to change the college, you might have to pay the complete fee, only then they would return you the certificates they have taken during registration of college, if not you can file a case on them and fight in court but remember colleges have good contacts with legal representatives.

Hope this helps.

Thank you.