Decide what type of Arabic you want to learn or study. If you want to learn Arabic so you can read the Qur'an in its original language, then you will want to study classical Arabic. If you want to learn Arabic so you can live and work in an Arabic speaking country, you should start by learning Modern Standard Arabic and then choose a dialect to focus on. If you want to use Arabic to conduct business in the Arabian Gulf, then you should start with Modern Standard Arabic and then specialize in the Gulf dialect.
Think about what type of program would work best for you. Do you want to study full-time in an academic setting or do you want to study part-time at a language institute? Do you learn better with group classes or with a private tutor? The University of Mumbai offers full and part-time academic programs in Arabic. You can do a bachelor's degree, master's degree, diploma course or an advanced diploma course. Diploma courses are usually part-time study. If you want something more flexible, look for a private tutor or sign up for classes at a language institute like Arabic Expert (www.arabicexpert.in).
Sign up for classes or tutoring sessions and start learning Arabic. If you are a beginner, you will start by learning the Arabic alphabet. The Arabic alphabet is similar to the Urdu alphabet, so if you can already write in Urdu it shouldn't take you too long to master the script. If the Arabic alphabet is new to you, it will likely take you a few months to get used to it.