CBSE 12th

Yes, you can join the cabin crew diploma course after class 12th. Please go through the link below.
https://www.shiksha.com/aviation/cabin-crew-air-hostess/colleges/colleges-india

Yes, For B.com (hons) course, you have the 'option' to opt for economics i.e., it's not going to be a core paper. It's an elective subject and not mandatory. If you wish to study economics as one of your subjects you can choose it as your elective, else there are other subjects (political science, Calculus, Physical Education, etc.).

Fees details are as follows: INR 8.40 Lakh (Fees Components: Tuition).
Security deposit (Refundable) of Rs. 15000 is to be paid with the above fees.
The fees mentioned will increase by approximately 5% every year.
Hostel Fee Details (if applicable):
Non-AC room: Rs. 60,000/- per annum
AC room: Rs. 1,00,000/- per annum
One time Refundable (Security deposit) - Rs.10,000/- (Mess charges on actual basis).

Hi,
You have various options like B.Sc BCA pharma, B.Sc Statistics and so on.

Hi,
The best courses after class 12th Commerce stream would be B.Com (Hons.) and BBA. B.Com (Hons) is a 3 year degree course that will enhance your knowledge by providing a detailed basis of commerce.
While on other hand, BBA is a professional course that will polish your business and management skills. Apart from these two courses, you can opt for BA in various streams, Law, Journalism, Hotel Management, etc.

Of course, you can either get in through Anna University/TNEA Counseling or contact College for the Management Quota. I am another state student studying in PSG
Check out the link below for details :
https://www.shiksha.com/b-tech/course/b-tech-in-information-technology-psg-college-of-technology-coimbatore-114894

Mechanical engineering and MBA are whole together a different field. Though, you can do MBA after ME, but if you want to pursue MBA, you have to have a Bachelor's degree. MBA is a management field, so pursue something that is related to business and management for e g. BBA.

You may have chances in ITM-Navi Mumbai, IES, SIESCOM, Bharathividyapeeth and Welingkar.

Hi Tanvi,
You can do anything that interests you, know your likes and dislikes, your aptitude and inclination towards a specific subject and decide. Moreover you have not mentioned your stream to suggest you anything further.