Hi,
It seems that you have a general issue in your MSFS2020 installation:
Here, from the WorldMap (our data installed):
… but as I mentioned before, the airport layout is completely out of date:
Against the real world:
These things have nothing to do with the fact that you can´t select VIDP as your destination or arrival airport; therefore, I guess you have another issue on your system, but there is no navdata issue.
Here is the stock A320:
VIDP is a valid code that can be entered without issue. I’m sorry, but this is not an issue on our side. Maybe you can find an answer in the MSFS forum.
Cheers
Richard