Hello,

First of the the eligibility criteria to appear for UPSC exam is passed graduation in any discipline from a recognized university, you can appear even in the final year of graduation, there is no minimum aggregate required in this case, the age limit for general candidates is between 21 to 32 years, relaxation is offered to reserved categories.

See, there is no such thing as best group/stream after 10th or specific stream after 12th that will help you qualify UPSC exam, the syllabus of UPSC is more humanities oriented as it includes subjects such as history, geography, economic, polity etc, now the only advantage people coming from humanities stream have is they are well acquainted with the subjects at 10+2 level or even at graduation, unlike say people coming from science/commerce/engineering background, if UPSC is the only aim in your life then you can go ahead with choosing humanities stream at 10+2 level and graduation with majors in subjects like history, geography, economics, law, political science, public administration etc, as there is considerable overlap with the syllabus of general studies and that of optional subjects.

However, if at this point you are not completely sure of only appearing for UPSC, and you have interests in other field such as medical/engineering or anything else, what you can do is choose the specific stream, complete 12th and graduation, work in the relative domain for few years to gain experiences and then if you still feel you want to appear for UPSC, then you can go ahead, also it's good to have a back up plan when it comes to UPSC, and if you look at previous year toppers they come from diverse backgrounds of that of medical/engineering/commerce/science etc which only confirms one thing that it's not your stream selection at 12th or graduation level that becomes the deciding factor of you success in an exam like UPSC, instead it's your personal attributes of single minded focus, dedication, perseverance which matters the most for all aspirants.