Dear Koushik 

Yes because during the prosses of taking admission you need to submit your document for verification

like T.C, character certificate and remain another important document and some time some amount of

registration fee. so some it affected you because of govt. colleges take all original document.

if you don't wanna trouble in future. I suggested please cancel previous college admission.

but don't need to cancel the registration is not affected you that much. it works as backups for you.

Good Luck.

  

Hello Kaoshik,
Yes you can drop your private college when you will take admission in government college.
You cannot switch but you can drop college. If you are in private college and next year you will got good marks for government College then you can get admission there easily and then drop your current college.
Good Luck!