I don't claim to fully understand Indian culture, being from the West. For you to be concerned about adultery I assume it does happen in your culture. However, would it be fair to say that if both you and your wife agreed to (or at least went along with) an arranged marriage, you both have a "traditional" family background? If so, would that background promote adultery? I wouldn't have thought so.
I won't say that the western approach to marriage is any more successful - the skyrocketing divorce rate shows that. But I do believe that marriages can be successful if you put some work in. In a way, you now have to do what westerners do before they marry. You have to court your wife!
It sounds like you have married and then plunged straight into a routine of work. You need to make some time for your wife, get to know her, and win her over. In a way it sounds like you may have yet to make a proper "first impression". Do you really want your first (or one of your first) in-depth conversations to be about adultery and faithfulness? I believe you need to talk about lots of other things first.
If you were to talk to a western counselor about saving a marriage, the advice many would give (and indeed the advice I was given) is that if your partner is having an affair (or hasn't embarked on one yet but is maybe on a course to) then you won't win them back by making accusations and causing arguments. The best chance of saving a marriage is to win them back by showing that your relationship is worth fighting for.
Show an interest in her. Talk to her about what she likes. Find things in common. Try and make her laugh. Only once you have a foundation for your relationship can you really open up and talk about fears. If and when you do reach the point of talking about your fear of her faithfulness, don't make it about her. Express it as what it is - your personal fear. The goal is not to make her defend herself over an accusation, but reassure you. Of course, if you build your relationship and start to enjoy a romance, you may get the assurance you need in a non-verbal way and hopefully you won't even need to have that conversation!