In general its a myth that if you study a subject related to government job subjects then it will help to crack the exam. But in general government jobs needs special attention and preparation. The course work you will study in graduation will have broad understanding and the pattern you will give exam in college will be broad and descriptive where as in Government exams you have to face the objective problems.

Thus I would say you should study a subject which is easier for you and you like the subject. This will help you not to feel the subject as a burden thus you will be able to focus on your exam preparation more.

To know more about Government jobs you may visit the link provided below:

https://competition.careers360.com/articles/government-jobs

I hope you got my point. All the very best for your future endeavors!