Hello Aspirant.

Take admission to an undergraduate course of your choice. Start preparing for UPSC along with it. This way, you will get at least three years of preparation time before your first attempt. You will be eligible for your first attempt after your graduation (or in the final year of your graduation).

One thing you can do is try and study the same subjects for your graduation which you want to choose for UPSC. This will make things a little bit easier.

Hope you find this helpful. All the best.