Priyanka,
Let me add some points, and this will help clarify your doubts.
1. Marraige is not the "end all" and "be all" of life. So don't spend all the time thinking on this, take a step back and look at overall life goals.
2. Build career, & Read and learn about - Literature, languages, culture, traditions, philosophy, religion, etc.. apart from the core career subjects of enginerring. This will be far more fulfilling in your life. Career will ensure you are financially independent and also support the fsmily if by chance, your husband loses his job at some point in life.
3. Assess every decision with pros and cons analysis. You should assess whether you want to marry at 21 yrs even before building a career. Read about people who married very young and regretted, understand the pros and cons.
4. Experience is irreplaceable - so take the inputs from seniors, don't disregard them. for eg, most people particularly those who come from orthodox or fairly religious conservative middle class families will turn to religion in a big way after 40 yrs, sometimes even earlier. At this time, people will regret choosing the wrong partners. Not specific to intercaste marrwiges. Even within community, if you marry an atheist and you turn religious at 40 yrs, you will regret the marraige everyday. Bad marriages do not start as bad, it all starts with love and hope, which turn slowly into a disaster if ideologies, interests, hobbies, careers do not match or do not complement.
5. Children - unfortunately, the biggest impact of inter caste marriages is on children. They will want to marry only with Tamil Brahmins, and most of them will reject the alliances. So in your 40s and 50s you and your partner, both will regret the marraige, seeing your kids suffer.
6. Age 21 yrs is not the time to make any decison that is life long. You will not have the experience to choose the the right life partner whether inter caste or within tambrams. And while divorce is always an option, remember it is not easy and will leave a lot of people upset, will be a painful process for you.
5. Ideologies - you seem to be a smart liberal inclusive girl, and open minded to take advise from others, so you definitely don't want to be married to a "Sanghi family" who will keep spouting anti Muslim hatred day in and day out. Your life will become hell listening to all that negative stuff. Trust me, you are living a great life now, studying, learning and staying in a protective environment with your parents. If you get into a bad marraige, it is all over. You will have to run day and night.
Ultimately, there is absolutely nothing or no one in life, that is worth rushing for and dying for. Not even when someone gives you a billion dollar, because you don't know what problems that money will bring. So take it easy, spend time with friends, and build a career, forget about love stuff for a few years.
