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It's always best to go for a regular degree (as compared to a correspondence course) whenever the option is available. Let's look at your dilemma in two parts for a holistic reasoning: (I) Whether to opt for getting a Bachelor's degree at all? (ii) Regular vs. Correspondence
Even though one can do without opting for a Bachelors at all if one is pursuing CA I suggest one should still obtain the degree for three reasons -
1. There is no guarantee one will clear all the CA exams in the first attempt (though I hope you do). You won't have any degree against your name to speak of till then. To me, that's a scary thought.
2. Till one doesn't clear all the exams, one's chances of employment decrease in a lot of places. Most places, actually, even if you've cleared IPCC.
3. You won't be able to go for higher studies because you are not the equivalent of a graduate till you clear your Finals. Now, let's look at the dilemma of a Regular vs. Correspondence course -
Academically, in a correspondence course, you will: (a) Not have direct contact with any college faculty. Even if you take private tuition, it's not the same as going to a college and studying under a professor.