Reading the books of 11th and 12th is required but they are not sufficient. If you want to go for the Reproductive Biology & Clinical Embryology course then you need to read your UG course books of Biology, Anatomy, Microbiology & Zoology will be required. So you should try to study in a comprehensive way and not only the 11th and 12th books.

For more information regarding AIMS consider the link below:

https://www.careers360.com/university/all-india-institute-of-medical-sciences-new-delhi

I hope this helps. Wish you a great eve!