Hi Kin Kim! 

Greetings! 

Did you mean IAS? 

OK.. i am answering this wrt to IAS NOT IS=Islamic State(..joking).

Indeed, doing B.A. LL.B. will give you an edge over others.

Firstly, this is because while dealing with various legal statutes and case laws an understanding develops, which will help you to solve various legal issues and related matters.

Secondly, if you will study seriously in a law school then you will get a good idea of subjects of arts like History, Sociology, Political Science, and Economics (Which will help you for UPSC). For subjects like constitution you can have mastery in law schools.

Thirdly, it is a professional course and is any day better than simply doing graduation, as you can practice in courts any day you decide to do so or maybe you can opt for the Judicial Services if you change your mind in 5 long years some people find it more reputable and peaceful job. In case you think that you can opt for three years LL.B. course after graduation, then think about the difference in the quality of education in both cases.

But one can argue that engineering is also professional course. For which you need to understand that it is in no way made for UPSC or any other social services. Students of engineering colleges who opt for UPSC only do so because they do not find satisfaction in their profession, and they have to do extra hard work to grasp subjects for UPSC. Therefore, you should opt for engineering if you are passionate about it and will remain in the same profession only.

Finally, as some people say that having an LL.B. degree helps one in promotions in many of the government organisations, senior IAS officers are preferred for appointment in law reforming committees because of their deep understanding of the law. For which many times you will find that government officials obtain law degrees while in service.

Decide wisely, as your career depends on it.

Please upvote if this was helpful to you. 

Thank you and good luck.