The Ujjain Observatory, also known as the Vedhshala, is the oldest astronomical observatory in India. It was built in the 5th century BC by the astronomer and mathematician Aryabhata.

The Vainu Bappu Observatory is located in Kavalur, Tamil Nadu. It is one of the largest optical observatories in Asia.

The Kodaikanal Solar Observatory, located in Tamil Nadu, is known for its contributions to the study of solar physics. It has been in operation since 1900 and has made significant observations of the Sun.

The Giant Metrewave Radio Telescope (GMRT) is located near Pune, Maharashtra. It is an array of 30 fully steerable parabolic radio telescopes, making it one of the largest radio telescopes in the world.

The Udaipur Cosmic Ray Observatory, located in Rajasthan, is dedicated to the study of cosmic rays. It has been in operation since 1964 and has made significant contributions to the understanding of cosmic ray physics.

The Aryabhata Research Institute of Observational Sciences (ARIES) is located in Nainital, Uttarakhand. It is a premier research institute dedicated to astronomical and astrophysical research.

The Udaipur Gamma-Ray Observatory, located in Rajasthan, is known for its contributions to the study of gamma-ray astronomy. It has been in operation since 1985 and has made significant observations of gamma-ray sources.

The Chandra X-ray Observatory is a NASA mission and is not part of the Indian Astronomical Observatory (IAO) operated by ISRO.

The Atacama Large Millimeter Array (ALMA) is a collaboration between India, Chile, and the United States. It is located in the Atacama Desert of Chile and is one of the most powerful radio telescopes in the world.

The Udaipur Infrared Observatory, located in Rajasthan, is known for its contributions to the study of infrared astronomy. It has been in operation since 1986 and has made significant observations of infrared sources.

The Indian Neutrino Observatory (INO) is located in the Bodi Hills of Theni district, Tamil Nadu. It is an underground laboratory dedicated to the study of neutrinos.

The TIFR Giant Metrewave Radio Telescope (GMRT) is located near Pune, Maharashtra. It is an array of 30 fully steerable parabolic radio telescopes, making it one of the largest radio telescopes in the world.

The Udaipur X-ray Observatory, located in Rajasthan, is known for its contributions to the study of X-ray astronomy. It has been in operation since 1989 and has made significant observations of X-ray sources.

The Goldstone Tracking Station is a NASA facility and is not part of the Indian Deep Space Network (IDSN) operated by ISRO.

The Vainu Bappu Observatory is known for its contributions to the study of optical astronomy. It has been in operation since 1968 and has made significant observations of various astronomical objects in the visible and near-infrared regions of the electromagnetic spectrum.