Hey yall, flying to VIDP/DEL in July and had some questions regarding the trip.

1) I am currently on Tmobile One plan that includes free international low speed data and msg. Any experience with the data quality? Will it be enough for using Whatsapp, uber, email?
2) I plan to grab a local sim card, however currently own an esim iPhone. Can I grab a sim card from the airport, if so which providers and what do they need? I will be traveling with some NRIs what do they need as well?
3) Im not an app power user, but have heard from friends that having access to particular apps before landing is beneficial to avail of service such as uber/taxi, whatsapp/basicallyeverything, paytm/tap and go services, rail app/booking tickets. Any lists would be greatly helpful. I would be a using non indian CC to pay will I have any issues using said apps?
4) Both inbound and outbound, booked on the same ticket, will have me transiting from the international to the domestic terminal, how does that work? Will i have to first deplane, clear customs, pick up baggage, talk to the transfer desk, recheck, perform domestic security check?
5) I wanted to spend some time at the holiday in express in terminal, anyone experiences of what to expect, and how the process works, and do i have to prebook?

1) In general I've found that T-Mobile's free internatinal service works fine if you download offline maps and any language translations that you might need. I travel to a lot of different countries and almost never bother with a local SIM/eSIM if I have T-Mobile service. I will say I don't use Instagram / Faceblech / etc. For Whatsapp, Uber, email I find it to be just fine. It's not as fast as at home, but it's perfectly serviceable.

5) You do need to pre-book the Holiday Inn express in the terminal. Upon arrival, you must to find the hotel's desk (there are signs with the info) and someone from the desk will escort you to the hotel. You can't get to the hotel by yourself. Also, the hotel's web site has this warning:

2. I wouldn't bother to buy a local sim card, too much fuss. Just buy a esim with data from Airalo, Holafly etc so you have good data coverage.
3. Paytm & co doesn't work with 'foreign' credit cards due to the two step verification required by the regulator / RBI. For uber the only way is to use the cash payment option or buy a uber (india) credit using your foreign credit card in advance. Recently the authorities released a UPI app for visitors, see the other thread in this forum on that topic.

Non-Indian Google Wallet does not work in India now

4. Exactly, the process has not changed

I have never had a problem charging my Indian Uber rides to my US Visa credit card. No OTP/2FA/other hassle.

I tried this on Ola, and it works except all transactions needed 2FA, which worked smoothly with Amex but not with my Visa.

Seconded on not bothering with getting a local SIM, particularly now that they've made it even more difficult and bureaucratic. There are things for which it's easier to have an Indian phone number, but the majority of those are also things for which it's easier (or mandatory) to have an Indian bank account. Food delivery apps work fine with U.S. numbers.

As for Uber, while it doesn't seem to be possible to add foreign cards to an account Uber thinks is Indian, if your Uber account is tied to your American number and already has an American card on it, it'll work fine. I've charged every Uber ride for 2+ years in India to an American card, which is great fun when I have to call fraud prevention for something else and verify that yes, these Uber transactions for $1.23 and $1.80 are also legit.

Apple Pay works fine in India. Google Wallet will block your access to see or change anything with your payment cards but it will still make payments from the default card when tapped.

Setting up UPI as a visitor is probably significantly more work than just paying cash.

I have the same plan. I have not had a problem using Whatsapp. Works just fine. But everything else is slow.

I want to purchase a local esim or physical sim.. Minus the kyc hassle, which is the best carrier for a 77+ day validity?

My criteria include
Data and Voice priority
Esim compatible
Pan india coverage but if need be a focus on north/northeast regions.

So far I have seen Airtels Truly Unlimited 84 day plan,
599 inr
6gb/day
unlimited local, std, roaming calls.

anything else I should be looking at like Jio?

Airtel coverage is patchy and outright terrible in many places. Jio is much better.