Hii
Medical stream is hugle ocean after you complete mbbs you can meke specialisation in any of the below
Feilds
There are many subspecialities (or subdisciplines) of internal medicine:

Angiology/Vascular Medicine.

Cardiology.

Critical care medicine.

Endocrinology.

Gastroenterology.

Geriatrics.

Hematology.
Many more
We have worked got the top govt college in Tamil nadu refer the below link
https://medicine.careers360.com/colleges/list-of-government-medical-colleges-in-tamil-nadu