Exam

Do your graduation and take coaching classes along with it.

Law, ethics, Geography, history, political Science, environment, Current affairs, aptitude and logical reasoning English and Indian language.
Read papers Regularly.

Sociology, syllabus and easily available but if you have command over your graduation subject then I prefer you to go for that. For getting good marks you need to prepare hard for one year atleast and also you can go for coaching. It's the toughest Indian exams for most intellectual minds.

IAS IFS and IPS are the most demanded services so those services are given to top 50-70 rank holders and for SC, ST top 22.

You can get lot of college from your marks in different entrance exam check every possibilities through Shiksha college predictor and sort them out for you if you are done with 2-3 option ask me or here. You'll get it clear. All the best and congratulations on your performance.

English and Indian language exams are must for UPSC exams.

Hi dear,
Yes, you can apply for both at a time, but you can enroll yourself only for one course at a time. If you enroll yourself for both of the courses, you will be departed from both of the courses.

Hi buddy,
You can use this link to find out which colleges you can get from these marks. This is Shiksha's official college predictor tool. Hope this helps. All the best. https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor?utm_source=connect&utm_medium=CR_JEECP&utm_campaign=6375912
Or

For JOSAA, you have to apply through JEE Mains and for WBJEE counselling, you have to apply through WBJEE.

Yes, you'll get decent government college for sure. All the best.