All 3 private companies offer 4G services across the country. Here we are comparing unlimited plan having data 3 GB per day or 2.5 GB/day with unlimited calls.
Comparison of Jio, Airtel and Vodafone for 3 GB data per day:

If one wants to buy plan of 3 GB/day unlimited data, then below is the comparison of all three 4G players of India. Also, the per day cost of data is given in the bracket to understand the real cost of plans in day term.
Plan | Jio plans for 3 GB data per day | Airtel plans for 3 GB data per day | Vodafone plans for 3 GB data per day |
28 Days | 419 (14.96/day) | 499 (17.82/day) with (Disney+Hotstar) | 359 (17.89/day) |
56 Days | 601 (10.73/day) with (Disney+Hotstar) | 699 (12.48/day) with Amazon Prime & Xstream | 699 (12.48/day) |
84 Days | 1199 (14.27/day) | 699 (2.5GB/day) with Amazon Prime & Xstream (12.48/day) | 901 for 70 days (12.87/day) with (Disney+Hotstar) |
Longer Packs | 2999 (365 Days) (2.5GB/day) (8.21/day) | 3359 (365 Days) (2.5GB/day) (9.20/day) with Amazon Prime & Disney | NA |
Compare all the plans of Jio
Compare all the plans of Airtel
Compare all the plans of Vodafone
Compare all the plans of Jio, Airtel and Vodafone at one place
Disclaimer: Kindly refer to the official website for any clarifications.