@lathaamenon - Hi there. I have one son who is in the third year of his PhD program (aerospace engineering) at Michigan, one who completed his biomedical engineering masters degree at Georgia Tech, and my youngest boy started his materials engineering masters degree at Lehigh in September.
I note that you say your student is “aspiring to join MS/PhD program.” Which one? The vast majority of US PhD programs admit students directly and typically do not award masters degree. This is a big change from when I went to college in the US and is not the practice in many countries. In fact, a university may warn that a student considering a PhD should not apply to the masters program but instead directly to the PhD program
Volunteering and extracurriculars don’t really matter. Teaching experience is not particularly important. Grades, research experience, and letters of recommendations are key for PhD applicants. Research experience is not that important for MS/MA applicants. Many students actually get research-based masters degrees to cure a lack of undergraduate research.
Another key point not all parents know (like this one when we started out). PhD programs are funded and provide a stipend for living expenses. Masters programs typically do not provide significant financial assistance. If your student wants a student loan, he/she fills out the FAFSA; parental income etc. is not entered.
Finally, when evaluating PhD programs, it’s all about the fit. If your student’s research interests align with a professor’s, your chances are much better than if there is no fit. Your student will likely be supporting the professor’s research interests and co-writing papers. What this also means is that your student will need to evaluate programs of interest. There is little sense in applying to a university without a fit. Even a mid-tier university could reject your student if there is no fit. Conversely, if there is a strong fit, your student may have a strong shot at a top-tier university with a good fit.
As an example, my oldest son has been interested since high school in electric/ion propulsion for space satellites and vehicles. He has also been interested in chemical propulsion. We visited Purdue, which is very strong in chemical propulsion, and Michigan, which is very strong in electric propulsion. After the visits, he decided that he was all-in on electric propulsion and focused his classes and research on this area his last two years of college. He got into two of the three universities he applied to, which both had good fits, and was rejected by one that was not a particularly good fit. His earlier visit to Michigan, meeting with the professors, and touring the facilities also helped, I expect.