Dear Vaishnavi,

For the preparation of IAS you have to to be a graduate and it does not matter whether you graduate with an MBBS degree or Engineering. You just have to graduate and there are no percentage criteria as well. So, if you want to prepare for it I suggest you to start reading basic books right after taking admission into any bachelor program of your choice as you can appear for UPSC right after the graduation degree and as you have ample of time so try to have idea about India History, Geography, as well as these, are the waste subjects and try to read newspaper daily this will help you to aware what is happening inside the world and also in our country.

I hope this will help you.

Good luck