Dear Nandita,

Here are a few colleges from which you can pursue PHD in Obstetrics and Gynaecology:

• All India Institute of Medical Sciences.
• Christian Medical College. 
• Armed Forces Medical College.
  
• Madras Medical College. 
  
• Grant Medical College.
  

The course fee range from INR 10,000 To INR 500,00 depending upon the college you choose.

Hope it helps.

Good Luck.