How someone from chennai did this when NASA and ISRO can't find it for months?
Its just possible from LRO orbiter from NASA since they make the pics available to public on their domain.
There you have the answer to the puzzle, since everything is publicly available the people who are enthusiastic about the space study will find time to monitor and investigate everything and that is what happened here, there are many talents sitting outside and this is a prime example, select people because of the merit and not because of recommendation and the system needs to change.