tm,
Please understand that my ROTC experience is 1) dated (graduated and commisioned through ROTC 20+ years ago (again, sigh, I'm getting old), and 2) through another branch in the service (AF ROTC).
But when I went through the AFROTC program, cadets would request the type of career field they would like to enter (flight officer, engineer, security forces, etc. (i.e. the multitude of others careers available)) between your Sophomore and Junior years. You would fill out a "dream sheet", stating which career field was your first choice, which was your second, and down the line. The service would then match you to the one field that best fits you and best matches their needs. They look at your desires, performance in school, aptitudes (i.e. standardized tests, cadets in AFROTC took something called the AF Officer Qualification test (AFOQT), which is basically like the SAT, but a little heavier in math and also with sections that tested your skills in reading maps and aircraft instruments (looking for capabilities as a future flyer). Again, dated information, so I would research if this is still the case, or even close to how it is done in Army ROTC), and recommendations from your ROTC commander.
Please remember, if your on a ROTC scholoarship before this point, you have already told the service you will enter the career field they are paying your education for. (Again: dated info. There may be "general" scholarships available. Current information for this young person anyone?) In my day, the AF was not offering pilot scholarships to freshmen and sophomores(career field was over-manned), only ones for navigators, thus my choice was made for me at an early time. But I can't complain how it turned out for me!
Basically, you're competing on a national level for the career field you want. The performance factors I mention above are used to give you a score, then they just go down the line matching cadet's desires until the pool of requirements is filled. Score high, and you will most likely get your first choice. Score poorly, and you may end up in your second, third, or even fourth choice. Please remember that no matter what, you are competing first and foremost to be an OFFICER, which is the most important title for all those newly commisioned. (And, in rare cases, you can compete later in your career to transfer to another. It does happen, but I find many Officers fall in love with the career their given and choose to stay (again, my case)).
Again, I remind you that this data I'm presenting is old and from another service. My ultimate advise to you would be to research all the branches and career field options available. Talk to the officers and NCOs in your ROTC unit and ask them thier opinions (what do they love about their career field, what do they hate). Ask similar questions on forums like this (but please be careful to filter out bravado and pride in some of the answers). Lastly, I am sure your ROTC unit will provide oportunities for you to get information on each career field either through presentations from presentations or classroom discussions. Research, my boy, research. This is you life we're talkig about, and only you can decide what you'll be happiest in.
If there are any individuals with greater resources and more accurate, timely information available for this young individual, please feel free to add to the discussion. Someone currently in (or recently commisioned from) an Army ROTC program would be a tremendously valuable resource here.
