I’m using airtel for the past 3 years and I never had any problem with it. Yeah it sometimes goes out of coverage but overall it is best network operator in my review. Their customer care service is also very active. I messaged them once and they replied me within 2 hours.
Internet packs are also not much expensive and the best thing is it is easy to hack for free net. I’m using free net for the past 3 weeks and also while writing this review and had no problem at all. Thanks airtel.