Design

You can be a product designer in two ways. Either, you do graduation (B.Des) in product design or post-graduation (M.Des) in product design (PD). There are various government and private institutes in India, which offer these courses.
If after your class 12th, you get into NID for B.Des course (4 years), then your first year will be foundation program and from second year, you will get your specific disciplines (product design, animation design, graphic design, exhibition design, film and video communication, ceramic and glass design, textile design, furniture design, etc.).
During one year of foundation program, there will be several courses which will be common for all students. Total grading will be done for all students and a merit will be created. Also, you will be asked to fill a form mentioning your discipline preferences (1st, 2nd, 3rd, etc.) for all remaining years. As per your merit number and preferences given, you will get your specific discipline. The problem here is, if after one year of foundation, you don't get enough grades to secure PD as your final discipline, then you might end up getting other disciplines and not PD.
The second way is, you finish your graduation (10+2+4) (B.Tech/ B.Arch/ NIFT) and appear for M.Des entrance exam for which you will have to mention the discipline at the time of form filling, you can apply maximum for 2 disciplines. If you get through, you will get admission in the same discipline you had applied for.
I hope it helps.