What are the top scientific meetings held in India?
The Indian Academy of Sciences, The Indian National Science Academy, and several subject area-specific organizations such as the Indian Society for Developmental Biology, the Indian Association of Neuroscience, the Indian Society for Cell Biology, Society of Biological Chemists- all hold annual or bi-annual meetings. in addition, several institutions organize topic-specific meetings in which leading scientists from all over the world are invited. These are often associated with workshops in a related field, led or taught by some of the visiting scientists. Examples: visit the websites of CCMB, NCBS, NBRC, IISc, IISER Pune, TIFR, to get a flavor of some of the past meetings. These include annual workshops and meetings on different topics of current interest, satellite meetings to other major meetings being held in the Asia-Pacific area etc. In general, there is a 'meeting season' between September-March (good weather) when a number of international meetings are held. There are also some workshop type meetings like the Mahabaleshwar meeting which have been held for >40 years annually and where there are usually a few international lecturers.
Specialized meetings focused on some fields are lacking in India - e.g. there is no meeting that covers plants, or ecology, or evolutionary biology.
Here's a creative example addressing this shortcoming: A group of 5 faculty working in the same sub-area, but in different Institutions got together and started arranging student directed meetings. This got the students in each of their labs talking to each other and the second in the meeting series was a Mahabaleshwar conference which was just awesome for both students and faculty. The meeting happens every year or two and it is a good place to get a few people in your area (build contacts) and more importantly get your students to grow intellectually in the area of your research. The travel portion (local ie within India travel funds, that are available on Indian grants) of your grant will also cover travel, registration and other costs of all your students which is a big plus.