Hello,
Yes , being a medical student you can definitely join the indian army as a medical officer or doctor. For that you need to pursue your mbbs from any reputed university and then join the army. Or talking about the other way , you can do mbbs from afmc , army forces medical college from where you can directly join the army as a medical officer. As of now make sure ghat you focus on your studies and perform really well.
Hope this helps
Good luck