Maths Spl

Yes, you are eligible for B.Com, BBA and MBA as maths does not play important role. Your overall percentage should be good.

There are many fields you can go for after BA. You have not mentioned your age as there has been a big gap. There are some competitive exams you can appear for - like civil services, staff selection commission exams, etc. but the maximum age eligibility. There are lots of job oriented courses as well but they all have age restrictions. But still there are many other courses where age is no bar. Few of them are:
B.Ed / MA
Fashion designing
Interior Decorator
MBA

Mechanical engineering would be a better option.

Mechanical engineering is the best core branch among all engineering branches for government jobs as well as research.

Hello Pragik,
Here are a few colleges of Bangalore:
1.Presidency College
2.AIMS Institutes
3.Christ University
4.MS Ramaiah College of Arts Science & Commerce
5.The Oxford College of Science
6.CMR University
for more college follows the link
https://www.shiksha.com/it-software/colleges/bca-colleges-bangalore
COLLEGE IN CHANDIGARH
1.Goswami Ganesh Dutt Sanatan Dharam College
2.Post Graduate Government College
3.Gian Jyoti Institute of Management & Technology
4.MCM DAV College For Women
5.DAV College
6.Dev Samaj College for Women
For more colleges in Chandigarh, follow the link:
https://www.shiksha.com/it-software/colleges/bca-colleges-chandigarh
Thanks.

There are some provisions for changing core subjects after your registration in class 11th in any board. Whereas, you can change your optional subjects by approaching the board office and completing formalities.

1) Statistics
2) Matrics
3) Matrics Space
4) probability
5) Discrete Mathematics
6) Calculus
7) Algebra
8) Analysis
9) Differential Equation
10) Differential Geometry
11) Economy
12) Number Theory
13) linear programming
14) Smaller Part of Digital Electronic.
I hope, it will help.

There are plenty number of government jobs from various department in India. First of all, you should choose the stream which you interest like UPSC or your state level PSC then you should prepare it well. Mostly government jobs eligibility is "graduate" in any stream.
All the best.