The Graduate Record Examinations (GRE) exam in India is organized by:
 

Educational Testing Service (ETS)

ETS is a US-based non-profit organization that develops and administers the GRE exam worldwide, including in India.

In India, the GRE exam is conducted by:

Prometric Testing Centers: Prometric is a leading technology-enabled testing and assessment solutions provider that administers the GRE exam in India.
ETS Authorized Test Centers: These are test centers that have been authorized by ETS to conduct the GRE exam in India.

Some of the prominent test centers in India that conduct the GRE exam include:

Prometric Testing Centers
IDP Education India
British Council
USIEF (United States-India Educational Foundation)

These test centers are located in various cities across India, including Delhi, Mumbai, Bengaluru, Chennai, Hyderabad, and more.