Accounting & Commerce

Try for One more attempt in November.
If you are dedicated toward CA, then you can definitely achieve it.
If you want to drop it, then you can go for MBA provided you do MBA from a good college so that it would be better for your future and Career growth.

Only if you are an oversea candidate or applying for the executive program.
Regards
Akshat

MBA after B.Com (Hons) is one the best choices based on job market data. My only advice to you that you must make effort to do MBA from any of the top 30 B-Schools of India. You may refer to following link for list of top MBA B-Schools in India:
https://www.shiksha.com/mba/ranking/top-mba-colleges-in-delhi/ncr/2-2-0-10223-0

For doing architecture, you must be a student of science stream that is you are supposed to give class 11th 12th in science you have completed your class 12th commerce, it's not possible to get admission in architecture after doing your graduation, you have one chance of getting admission in architecture while doing MBA in architecture that's totally external and it's risky.

It doesn't make any effect for doing CA CPT, you just need to complete your 12th. While studying for CPT ,you should clear all the subjects with more than 40% including maths and your aggregate should be more than 100 out of 200 for doing CPT. You are supposed to be good in maths, study well, you can do it.

For joining Indian Air Force, the student must be a 12th science pass and not from the commerce stream. If you are interested in going for Indian Air Force, you must give class 11th and 12th again with science.

You are studying in 12th so you should currently focus on CPT and you have a good chance of doing CA, CS, CWA as you have interest in doing accounting and finance.