I don't know if they have any such algorithm in place. However, here's my experience.



On a late February night, I was travelling from Nasik to Secunderabad with my mother. We had earlier booked a ticket on Devagiri express - the two of us, in AC 3 tier. And as the wise fellows suggest, I didn't forget to check the "Consider for auto-upgradation" while booking, because who doesn't want to make sure they tried their best in getting the berth of their choice.



The train was scheduled to arrive at 1:00 a.m. and we were preparing for dinner at 9 p.m. before leaving. A message from IRCTC drew my attention - my mother's seat had been upgraded to AC 2 tier.



My mother was not sure about that. She has never traveled long distance by herself. It was either with my dad or me or my brother. I, having read this particular Quora thread itself, consoled her that IRCTC does this "all females in one place" thing to ensure safety. And she seemed satisfied with that.



When the train came to the platform at 1:30 a.m., I proceeded to help my mother first, to procure her seat. And to my surprise, all people other than her in the AC 2 tier coup were men in late 30s or mid 40s.



There was one Sardarji whose nasal growling would scare a tiger and then there was this man who would ask you to switch the light off because they were sleeping. Of course, two other directly asked my mother which place they were in, in Bhojpuri Hindi.



I asked the TT if it would be possible for me to exchange my seat with my mother. The TT was clear - he was not authorized to do seat allocation across AC 2 and AC 3 tier. What IRCTC had done was final.



I came back to my AC 3 tier compartment. Expected some angry voice to put forth their concern about switching on the light at this odd hour while I put down my luggage. The train had started to move, so the compartment was shaking and vibrating as well. I almost tripped over someone sleeping in the other lower berth, and woke them up.



To my surprise, it was a female voice, asking me which station we were in. And added surprise, there were three more female looking at me like the Eagle in their nest from their upper and middle berths.



Turned out, other than one more guy in the coup, rest of the six people were female. I couldn't make out in the dark properly, but seemed like they won't be older than 30.



I laughed at myself for this irony, and fell asleep wondering if IRCTC implemented the algorithm with a bug when it comes to auto-upgradation.