Apple ID problem!!!

So recently i logged out of my apple id on my only apple device. When i tried to login again it asked me two step verification code, which was apparently sent to my old phone number. I pressed on "didn't receive code" option and pressed on "more options" there it asked me to confirm my phone number number. When i entered my old phone number it said that it is wrong. Then i realized that the phone number was 11 digit long. But we 10-digit phone numbers in India. I tried to add a 0 in the beginning as well but it is not working. someone please help me out. i have a lot of data save on my icloud. please help!! Thank you.