In a post-launch address from the Sriharikota launch port, K. Sivan, Chairman of the Indian Space Research Organisation(ISRO), hailed the event as a textbook launch of a very important and complex satellite.
I'd imagine that in Indian English textbook launch means the same as it does in British or American English.
In this context, the textbook is being used as an adjective -
Textbook - (of an example of something) extremely good, or thought to be usual or typical
So a textbook launch is a launch that proceeded exactly as it was planned to do, without any problems.