Just my point of view.
So 18 lacs per year i.e. 54 lacs in 3 years.
With interest, probably 65 lacs.
If you can get in your city, then you save on hostel, etc…
You might earn around 6 lacs per annum i.e. 18 lacs in 3 years.
You will have around 47 lacs on your head after 3 years.
Considering your put in 10 lacs in loan per year, you might take another 5 years to complete.
Stronger suggestion try taking from someone you know who can give without interest.
Removes the headache of banks. Don’t think about selling any property or anything.
I know it takes a lot to repeat but not sure if that is the right thing to do. A good counsellor would be able to guide you as well. 21k isn’t a bad rank. 18 lacs for your rank for md medicine seems more. I am sure you can get in a college for cheaper. One more thing, I feel private college with lesser fee wouldn’t harm. 5 years later no one will care.