CBSE 12th

No this will not affect in MBA placement drives. The placement drives are conducted on the basis of CGPA/ Percentage obtained in whole MBA courses.

Yes, you can take admission in BCA course. The eligibility criteria is varying according to Universities. Few of them are asking about Maths at class 12th level, while for some Universities Math is not necessary in class 12th.

If you are doing B.Sc in Food Technology, Than no entrance test is needed and the admission is based on class 12th marks. However, if you wants to do B.Tech in Food Technology than entrance exam is needed.

The eligibility criteria of B.Sc. (Hons.) Chemistry of Jadavpur University is given below:
Eligibility criteria : Candidates having passed 10+2 Examination from any recognized Board in Science with Chemistry, Mathematics, Physics and securing at least 75% marks in average obtained in Chemistry, Mathematics & Physics are eligible.

Just ask yourself first, what he wants. You have appeared in JEE Main also, so what percentile have you obtained? If your percentile is above 95, then you can get the NIT for pursuing the B.Tech courses. You have another chance of improvement about in JEE Main May-2020 exam. Try to improve your JEE Main score further so that you could get the top NITs. So, in my opinion, you have to completely focused on JEE Main May-2020 exam after that you will be able to take the right decision.

Yes, you can take. The eligibility criteria of B.Sc (Hons. ). Agriculture through ICAR AIEEA UG 2020 is class 12th with a minimum 50% of marks in PCB/PCMB/ PCM/Inter-Agriculture.

For Delhi University, you have to register first with the official website. Application process is online only. DU will open admissions in June, most probably in the last week. Then in second or third week of July, they will release merit list having percentage at which they are providing admission.
www.du.ac.in

The eligibility criteria of DMS IIT Madras for MBA course is Graduates (or professional qualification equivalent to that of a University degree recognised by the UGC) in any discipline with first class or 60% marks (55% for SC/ST/PD) earned in their degree from a recognised/reputed University. IIT Graduates who have obtained a CGPA of 8 and above on 10 are exempted from the CAT score. So your academic profile is good enough for DMS IIT Madras for MBA course. The expected CAT cutoff for DMS IIT Madras for MBA is above 98. Hence, you have to score above this.

In my view you have knowledge of biology and maths, so you can opt B.Sc. Biotechnology course after 12th class. Because biotechnology is a course that includes many subjects like microbiology, Genetic Engineering, Agriculture as well as plant Biology. You can choose any subject as career after B.Sc. Biotechnology. For best placements, choice of good college is Important. In my area, PCTE College of Biotechnology offers B.Sc Biotechnology. College offers practical exposure to all subjects offered in degree by having industrial visits and guest lectures of experts of this stream.

For doing BBA after class 12th, maths is not compulsory. Eligibility says 10+2 in any discipline. There are many colleges that offer BBA like SP Jain in the western part of India and if you are looking for Delhi NCR then colleges of DU, IP and IILM University Gurugram are the options that are available.