Medicine & Health Sciences

Hi,
Yes, of course, there are lot many fields other than medicine and engineering. If you are good at math and want to be a scholar, you can pursue Bachelor in maths Honors and also, you can pursue Bachelor in biology Honors too depending on your choice and if you think, no, I won't to pursue both of them by doing B.Sc as well. This option is if you want to go in teaching profession!
Also, it also depends what you want to be in your life in long haul because being good at maths and biology at 10th level is totally different from being pursuing something on an extreme level because 10 and 11, 12 have difference.
And as far as PCB and PCM are concerned, you should decide what you want to pursue then only opt for something. Like if you want to do something in zoology and botany then you can go for PCB, if you want to be a scholar in mathematics then you can go for PCM.
So, basically, it's your call depending on the career you want to opt for.
Good luck :)

You should definitely go for further studies after the B.Sc. In India the job scope for Bachelor's degree course is getting thin by the day. Companies are now demanding Post graduate students. The only exception here is Engineering students. After B.Sc in non medical, you are presented with some good options. Here are few options I would recommend to you.
MBA
Masters in Business Administration is the first option in front of you. It is a 2 year long post graduate course after which you will be able to apply for jobs in management, accounting, finance, marketing related fields. To get admission in a MBA college you would have to appear in one of the entrance exams.
B.Tech
Engineering is another great course you after completing the B.Sc course. These days AICTE allows B.Sc students a lateral entry in the Engineering college. What Lateral Entry means is that you will get admission in the second year of the Engineering course, whichever you may choose. Most institutes in India reserve some seats for the lateral entry candidates. It ranges from 5 percent to 10 percent.
M.Sc
Another good option for you is M.Sc course. Once you complete your post graduate course, apply for entrance exams like NET and SET. If you fared well in these exams, you will get lecturer job in reputed college in India. If you are interested in teaching field then I must suggest you to do M.Sc course.