How do you dial a cell phone number outside the India?

To dial any telephone number in India from Another Country, replace the trunk prefix 0 at the beginning of the Indian domestic telephone number with India's telephone country code, +91.

If you are calling on a mobile phone, just enter the number in international format, beginning with +91, including the plus symbol.

Otherwise, replace the plus symbol with the international access prefix (depends on YOUR location).

(The plus sign means "insert your international access prefix here." From a GSM mobile phone, you can enter the number in full international format, starting with the plus sign. The most common prefix is 00, but North America (USA, Canada, etc.) uses 011, Japan uses 010, Australia uses 0011, and many other countries use different prefixes.)