Apple India — IPhone not catching 2G or 3G network

Address: Gurgaon, Haryana, 122002

Website: AppleCare

I have bought iPhone 6s 2 months back. I was using airtel 4G sim and all was going fine. But 1 week back I used reliance jio sim and from then I able to use other sim as not able to get 2G or 3G network or able to call or receive any call. After inserting jio sim this problem has occurred that my phone is only using 4G network for internet and nothing else going on.
I have reset all thing but still this problem has not solved.
Request you to please solve it this problem immediately.