Well, whatever side effects you get, they'd be better than getting rabies. Only two people have ever survived that disease.
I've never been vaccinated for rabies, but I do keep up with other vaccinations--flu, tetanus, y'know, that kind of thing. And of course my cats get their rabies vax every year. Tiny's first shot had him tired for a day, but other than that, they never showed side effects.
You can be vaccinated after exposure. Rabies takes long enough to get through your nervous system that if you go to the doctor right away after being bitten, you can get immunized and protect yourself. Vets and anybody who works with bats are usually vaccinated beforehand, because bats can transmit it without you really noticing, and vets just get bitten often enough that it makes sense.
If you want the "just in case" version, I would suggest: Schedule the vaccinations on a Friday. If your immune system kicks in and makes you feel crappy for a few days, you'll have the weekend to recover. I believe it is a multi-vaccine series; so remember that the second one may well be the one that makes you feel worst, because the first one tells your immune system what to fight, and by the second one it's starting to get ready to do so--resulting in the tiredness, fever, and achiness of a typical vaccine reaction.
I don't know whether India has a high rate of rabies. If they do, and you will be in places where it'll be difficult for you to get to a doctor, then getting the vaccine makes a lot of sense. Will you be in small towns or in the country? If you're gonna be in the city, near hospitals, I wouldn't worry--if you got bitten you could just go to a hospital afterward. English is a very common second language there, and highly educated people like doctors tend to know it, so I wouldn't worry about not being able to explain what happened.
If you have ever had a severe reaction to a vaccine before, I would suggest you get the vaccinations before you go, if you are going to get them, because that way you can stick with the doctors who are familiar with you and your health, instead of having to go to a new one in India.
The problems to watch out for with vaccine reactions include:
Feeling as sick as you usually do with the flu--high fever (102 or more), chills, exhaustion. Call the doctor if that happens. He'll probably just say "take some ibuprofen and get some rest", but y'know, better safe than sorry.
Allergic reactions. Hives, usually. Anaphylactic shock is possible if you are severely allergic (you would know about this already, if you are). Do NOT get the egg-based version if you're allergic.
If you are worried about allergic reactions, stick around at the doctor's office for an hour. They'll show themselves by then, and you can get immediate treatment.
The modern rabies vaccine is no longer made from neural tissue--it's grown in eggs, or in human cell cultures. So don't worry about the possibility of any symptoms related to that.
Effectiveness... two to three years. If you'll be there longer, I guess get a booster.
Have fun in India. Can I ask what you'll be doing over there? Studying? Visiting relatives? Sounds fascinating--I live in the US and I haven't left the country in ages. I wish I could visit India.