Within India there is nothing wrong in using this word; we all understand what it means. The fact that native speakers don’t use it is not our problem. After all, when you have `postpone’, then why not prepone? Dictionaries which contain a section on Indian English always include “prepone”. Native speakers of English, as I have mentioned several times before, use the word “advance” instead of “prepone”.
*I want to prepone/advance my date of journey. *Ganesh preponed/advanced his trip to Australia.