UPSC

Go to the official website of UPSC.

No, there will be no effect of that.

GATE is for engineering aspirants. If you want to study further in engineering then go for UPSC CSE.

Don't go for name. Big coaching centers just make fool to new students. The key for success is self study. So focus on it. You can take admission in a simple coaching.

There are not too deep questions from engineering subjects but there is something basics related to current affairs. Check the papers: Kindly have a look at the question papers from the link below. https://www.shiksha.com/exams/upsc-civil-services-exam/question-papers

For that, you have to clear the prelims, Mains and interview conducted by UPSC.

History, geography, political Science, economics are the main subjects for UPSC exam. Then some general mathematics and Science you need to study.

Yes, you can apply for UPSC exam career after BBA are as follows you can open your own business you can be a chartered accountant you can get job in hotel management field etc.

There are so many coaching in all over India. We can't say best among all because education nowadays has become a money earning source for everyone. So, everyone's motive is to earn money. They just guide you, the man's work is to be done by you. So be confident wherever you take admission just focus on your studies I am studying hard best of luck for your future.