I have been in your shoes and know what it feels like.
Your parents wants to secure your future and government jobs are a way to do that.
MBA revolves around your managerial skills and give you a managerial job after your graduation.
Buit before that, you have to bag a seat at one of the top colleges. Pursuing MBA in an ordinary B school or a low rtier one will be a loss of your resources, time and future as well.
I would suggest you to gear up and study for CAT, CMAT, SNAP. That way you will be fluent in aptitude which is also useful for government jobs exams. Attempt the MBA exams as well as the SBI PO, RRB exams that come your way. They will be good mocks for you even if you dont want to go for it. Those exams take long time to process the results. So you can get busy with MBA exams as well. When you crack one, you can always decide what you want to do later.
There is no harm preparing for both. :)
Government job is a very good option for the career growth in government sector. However, if you are planning for MBA you need prepare for the entrance exams like CAT/XAT/IIFT/CMAT/MAT. The only advantage of doing MBA is you can apply for government jobs directly without giving entrance exam and is more efficient to grow towards career.
Wish you good luck.