There is a right order to this, and most people run it backwards. They begin with a job title, work back to a course, and only then discover the entrance exam, the cost, or the subject they did not take in Class 11. By that point the decision has quietly been made for them by a constraint nobody checked.
One: settle the constraints first
Before any option is worth considering, three things need honest numbers. How many years can be spent studying before you must be earning. How much the household can actually put in, including the years of not earning. And which subjects are already taken or already closed — a route that needs Physics, Chemistry and Biology is closed to somebody who took Commerce, though a bridging or open-school route usually reopens it.
Constraints are not a smaller version of the question. They are the question. A plan that has not been costed is a wish, and it is better to find that out in an afternoon than in year three.
Write the three numbers down where the rest of the household can see them, because the person who will be asked to fund year two should not be hearing about it for the first time in year two. A choice that has been agreed out loud survives a bad semester; one that was assumed usually does not.
Two: narrow by what you are like, not by what pays
Salary is the easiest thing to compare and the worst thing to lead with, because published figures describe the top of a field rather than its middle, and because the gap between fields is smaller than the gap within one. What differs far more is whether the daily work suits you — and that is what interests, reasoning and work values are for.
The two mistakes that cost the most years
Choosing a field because a relative did well in it, and choosing one to keep a door open that you have no intention of walking through. Both feel like caution. Both usually cost two years.
Three: test three options before committing to one
A shortlist is not a decision, it is a research task. For each option, establish the entry route from where you stand, the second way in when the first does not work, and what the job looks like on an ordinary day. Every one of those is a matter of public record; none of it requires anybody to sell you anything.
Then get contact with the work itself — a shadowing day, a short course, a volunteer stint, a project you finish. Ninety days of real contact settles questions that no amount of reading will.
Four: decide, and write down what would change your mind
Commit to one route with a dated plan: what you study, what it costs, and when it starts. Then name in advance the point at which you would stop and what you would do instead. Deciding that while nothing is at stake is what keeps a career change from becoming a trap later.
If the decision in front of you is the stream after Class 10, that one has its own page — all five compared, with what each keeps open and closes off: The stream decision.
If you are earlier than this and still trying to narrow the field at all: Which career is right for me?.