BBA

If I am not wrong then you are asking for Bachelor of Management Studies, right?
There is not an obstacle for directly taking admission in BMS after PCM. You just keep your intermediate percentage on the higher side and directly apply to the college you want to pursue BMS.
Your mathematics will be more useful but not with integration or derivatives but with other tools. As a science student at first place, you could do it very well.

It is not so with most if the colleges, even IIMs take a lot of freshers with no work experience.
Talking specifically about your profile, I guess you should consider work experience as well. It will value-add to your experience and will be good for an MBA if you later decide to do so.

Hello,
It depends on your interest. Having study BBA for three years, you can better judge if management is for you.
If yes, then definitely go for MBA.
If you don't have any specific thing in your mind, then I would suggest you to go with General Management.

Hi,
You can check with the students who have given the exam. Or you can search it online.

You have a good work experience in a known Bank and decent academic profile. You can prepare for CMAT/ATMA and try to get into institutes like NIBM, IFIM, and IFMR known for Banking, Finance, and Insurance. To get into good institutes you need to write an exam either CAT or any other like CMAT, ATMA, SNAP, IIFT, TISSS, NMAT.

If you really dream to be a part of aviation background, there are very few colleges that offer BBA in airport Management.
Some of the top colleges are Singhania University-Rajasthan, IIKM-Chennai, UPES-Dehradun and Goenka University-Gurgaon. Best among these is UPES, but yes it is super expensive.
If you have aviation as a long-term dream that interests you and can afford, then this can be the best career option.

You should opt for BBA+MBA.