Airtel Airfiber is better than Jio Airfiber in my opinion. With Jio Airfiber, you get 30 Mbps speed with the lowest plan, and it's exactly 30 Mbps. You are not going to get more than 30 Mbps.
With Airtel, the lowest plan provides 40 Mbps, and you often get more than 40 Mbps, typically around 50 Mbps. Another advantage is that with Jio, the setup box also runs on the Internet. This means that when your TV is on, watching TV consumes both speed and data. However, with Airtel, the DTH does not require the internet to watch channels, allowing you to use the full 50 Mbps speed while watching TV without consuming data for TV channels.
Additionally, with Airtel's 100 Mbps plan, you often get around 120 Mbps speed, whereas Jio provides only 100 Mbps. Another significant benefit is that if you have an Airtel Axis credit card, you get a 25% cashback on your Airtel bill.
This means if you choose the Rs. 899 Black plan, your monthly bill will be around Rs. 1060, and you will get Rs. 265 cashback. So, your 100 Mbps internet and TV will cost only Rs. 795 per month after cashback.