Should international students mention if they have any career plans in the potential host country?
Tricky, tricky. In many countries, consular interviewers will definitely reject visa applications for this. In the US, they’ve gotten significantly looser in the last 5-10 years, but with the “regulations” always in flux, we never know what will happen. If you think this is a possibility, then no, don’t mention it.
Instead, if the essay prompt demands you write about your career goals, then state that you plan to return to your home country to work in companies similar to those you’d love to pursue abroad.
“Upon graduation, I plan to return to India to seek employment in a private DNA-sequencing startup like Ganit Labs or Medgenome, and thus contribute to this industry which I believe will make a huge impact on my country’s future.”