MCA

No, you have to complete and pass in all the subjects then you take admission in MCA . Because where you take admission in MCA they check your all the documents related to BCA. 

The total tuition fee for Amity Jaipur MCA course is INR 3.64 Lacs as per an unofficial source. Aspirants are required to pay the course fee after completion of all the selection rounds to confirm their seats. Admission to MCA course is based on merit in the last qualifying exam. In case, a candidate is unable to pay the fee within the specified time, his or her admission will stand cancelled. The application fee is waived off for admission at Amity University Jaipur. 

Candidates who have passed graduation with Maths or graduation without Maths in Class 12/ BSc IT/ BCA can apply for Amity University Jaipur MCA course. Candidates without Mathematics in Class 12 or graduation, can still apply, by availing the option of a bridge course as per the norms of the university. Additionally, the university shortlists candidates for MCA course based on merit in the last qualifying exam. Once selection rounds are over, candidates need to confirm their seat. They are called for document verification and course fee payment to confirm admission.

Yes, but you have math as a subject in your BSC. There's many entrance exam to take admission to top prestigious college of India like NIMCET, Mah CET, cuet, .etc. .