Which graduation course shall I pursue before doing MBA?

Dear, You can pursue MBA. For MBA, basic requirements are you just have to complete your graduation in any field whether it is commerce, science and engineering field. And, as I read your comment that you are from science background, do not worry about that. You are eligible to do MBA.

If you want to do MBA (Master's degree in Management), you are eligible, if you have any Bachelor's degree. But, B.Com and BBA is beneficial for MBA.

You can go for any field before pursuing an MBA as per your interests. For MBA, basic requirements are you just have to complete your graduation in any field whether it is commerce, science, and engineering field. Good wishes.