Airtel! it seems pretty large company and by name many people judge things but let me tell you one thing brand doesn’t matter what is its service! Airtel is not upto mark I would say because it sells it’s products expensively, but this network is not good at all area!
For Roaming Purpose it is good!
If you own a dual sim device! You should at least have Vodafone or Airtel.
Pros-
Good network covarage
Cons-
Good but not everywhere.
Expensive plans
If you thinking to buy a new Airtel SIM card you should go to airtel.in / leap to check if Airtel is good at your area on not!