Hello,
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Are you asking about if college doesn't give my certificate back if I get a seats?
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If it is,then obviously every college focuses on students best Career..
As you found you Career in some other course rather then what you are doing.
Then, you are allowed to go. There's no college who can reject you.
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After getting qualified visit college explain them the situation.
Visit vice principal or admission faculty.And after you gave your details you will be told to do some formalities like giving a letter or paying fees for cancellation. No bigger tasks will be given.
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And don't forget to visit college with parents. There will be no much value given for student visit.
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Hope this was relevant to your question.If not please ask for further information.
Thank yoi