How many days,months of practice & hardwork are required to pass the following exams with very good score which will provide a seat in top

You can write all exams after you complete UG or if you are in last year of required UG course. So if you are doing PG you can give exams. You can't give all exams at a time so, try to choose one and focus on it.
Every exam require atleast an year of coaching.
For reputed coaching search on quora for exams and city you want. Eg. for UPSC LA excellence in Hyderabad is famous.