Cellular phone operator Grameenphone is going to offer iPhone 6s and iPhone 6s Plus, the most advanced iPhones ever, from November 5.Customers can pre-register iPhone 6s and iPhone 6s Plus beginning on Friday, October 23rd at http://www.grameenphone.com/personal/iphone-6s, said a Grameenphone press release on Saturday.For more information on iPhone, please visit: www.apple.com/iphone.