Class 11

Yes you can apply for that college and just wait for the dates on their respective website and signup as well there.

Practice! Try to understand the concepts completely. You need help. As you have mentioned that you preparing from home. Use Google and other websites to understand the concept and doubts. NCERT is very important, try to finish it and then revise again and again.

You should join a good coaching center. You will find good competition there. To prepare well, you need competition and guidance that will motivate you for your studies.

Yes, mathematics is highly important for you to appear for UPSC exam. So, it's better to have maths as a subject.

You have already pursued HSC (with Physics, Chemistry & Biology) and passed also. So, now again you cannot pursue a separate subject for getting into admission after studying. So, don't waste a year on this. Pursue what is applicable and eligible and start your professional life.

Hi Amoghha Prakashgupta
Kindly predict your college in this college predictor. JEE Main rank predictor is an online tool which predicts the candidates rank range and probable colleges based on the difficulty level of the examination, average marks scored in JEE Main and seats available in IITs, NITs, GFTIs, and other SFTIs. The rank predicted might not be accurate but it certainly does give an idea to the aspirant. Know your college admission chances based on your JEE Main Rank, Home State, Caste, Gender, etc. Here https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor.

According to me, you should be choosing science because then you can take admission anywhere in the world if you are good at it, but eventually, you should be choosing whatever interests you.

You have done B.Sc in hotel management, you can take any subject in Bachelor of Education whether be it business studies economics, arts, etc.

Some of the schools are:
The Orchid School,
The Orbis School,
Symbiosis International School,
Sanskrit School.