The OTA for india was indeed 20a and not 20b which is odd to be honest.
The build number, the baseband version are all same as 20b though. It might be just the naming change LG is employing in different regions. I had flashed my unit to 20b a while back and received OTA on my friend's phone which was 20a. Here are the screenshots.
20A (India OTA)
20B INDIA/INDONESIA/PHILIPPINES kdz
Then LG screwed up by giving the wrong version number to the OTA. Full image KDZ beats partial image OTA.
The fact it says IND 20B refutes any other allegations. It's official LG firmware for the India H930DS. And it's full image KDZ.
I've got the India 20B KDZ posted. See link in post above.
INDIA/INDONESIA/PHILIPPINES share parts of the same KDZ, but the software auto-detects what phone you have (maybe by IMEI?) and installs the version for your country -- in this case India. 20B for India.