B.Sc

If you are solely into IAS, it is better to opt for arts. It will be very helpful for you as most of the course of IAS is covered in its syllabus.

B.Sc in any subject won't fetch you a good job. You need to pursue Master's degree as well as some specialized course after completing B.Sc to get a lucrative job. The choice of subjects are based on your interest and inclination.

Yes, you can opt for regular B.Sc and also pursue a Diploma course in some specialized area.

Hello Avinash,
I appreciate your interest to pursue Bachelor of science (B.Sc) in computer science from Pune. To assist you in choosing the colleges to pursue the same, you can refer to the below mentioned link:
https://goo.gl/PvzpjA
I hope it helps. If so, kindly upvote this answer. If you have any further questions, kindly revert.

Hello,
It is better to pursue MA in economics after completing CA with B.Com. Two UG courses will not fetch you anything good.
All the best.

Hello Rohit,
I understand and appreciate your interest in pursuing B.Sc in Economics. To assist you in choosing the colleges to pursue the same, kindly refer to the link below for more information on the colleges:
https://goo.gl/U7ZaU8
I hope this answers your question to your satisfaction. If so, kindly upvote this answer. If you have any further questions, kindly revert.

Biotech, Biochemistry or Biomedical sciences have excellent scope in India. Lots of positions are available for this disciplines in government as well as private companies.

Check the link for NAAC A graded universities:
https://goo.gl/wIKyqU