Going to New Delhi for friend's wedding

I posted on here before but the trip did not happen due to a death in the groom's family.
We are now rescheduled to go over, on 23 June, for 4 nights and returning on 28 June.
We have two children coming with us, age 7 and 4. The younger one has autistic spectrum disorder but is ok coping with travel - the main problem is him biting his nails so a bit worried about him picking up germs...
Any advice from anyone about what to bring or pack, and anything general we should look out for? I've been reading the threads on here a lot and we are all vaccinated.
We are staying at the Park Plaza in Gurgaon.
Thanks in advance!

Hand sanitizer, immodium, rehydration salts.

Got all those! Thank you! Anything else I might have missed? And do I need to be concerned about wearing leather shoes or sandals since cows and cowhide is sacred? Will leave the leather handbag at home...

It's going to be HOT in Delhi. So, yes, bring on those sandals. We all wear them here - leather, cloth, jute, whatever. It doesn't matter. I'd also suggest wet wipes. You're going to need lots of those. Cotton clothes only - even for the ceremony. Don't go for the silk/polyster variety - you'll regret it.

please treat this as a friendly advice, nothing more...
india (& indians) in general is not too aware (& thus empathetic) of ASD (we watch movies but forget everything when lights are on). they typically expect all special children to be either at home or special schools, but not mingle across society.
so don't expect strangers, authorities, service providers or even your casual acquaintances to be 'understanding' when tantrums start.
i have no idea how moderate or severe your kid's ASD is, but in general the cacophony of visual/audio signals are a bit too much when you land, especially coming from a developed country.
i recommend traveling with as much familiar stuff (books, audio, video) for the kid as possible to let him get adjusted.
there are lots of places in delhi to engage kids, so make sure you treat him to those after the awful signals he needs to tolerate at a typical indian wedding...

Fortunately my lad is pretty easy going and is not bothered by lights and loud noises! He communicates using picture cards and isn't very prone to tantrums. Hopefully we will be ok! But thanks for the advice, it's good to hear back about what we might be encountering out there!